How to make proper French Onion Soup

It's all in the seasoning (and I have the perfect candle to accompany your culinary adventures)

In partnership with Cornish Sea Salt

The air has changed. The first chill has set in. Welcome to my official calling signs for “I’m making French Onion Soup from scratch!”

When the end of Autumn sets in, others feed that pang with baking or bread-making. I simply must surround myself with wafts of caramelised onions and scorched Gruyere.

French Onion Soup is the first thing my husband John and I look for on a menu if we’re out at a restaurant. We’re way past the point of polite breath odour as an ancient married couple if it means ploughing into a big, steaming bowl of volcanically hot oniony broth topped with melted cheese croutons. Phwoar. Just writing that is my version of Rivals.

So last weekend, I roped in the kids and got slicing, sautéing and blow-torching, turning our no-plans Sunday from could have been a screen-filled, irritable, tidying-everyone-else’s-mess afternoon, into a wholesome, flavour-packed and fun culinary adventure.

The secret ingredients to cooking with kids? A chilled, calm environment (with a bit of Fleetwood Mac in the background, obvs), where you let go of perfection and set a positive and creative scene. I do this by prepping little work stations for them, giving them jobs that make them feel important and useful, and letting them contribute to the actual flavours of the meal, which they’ll be able to taste later on.

And, bien sur, because it’s moi, there’s always a scented candle nearby!

Given the potential olfactive assault of a mountain of freshly sliced onions, I chose to light this sensational Sea Salt candle, newly launched by Cornish Sea Salt in collaboration with Keynvor Candle Co. The candle is inspired by the coastal landscapes and billowing sea spray of Cornwall’s beaches, a stone’s throw from where Cornish Sea Salt produces their beautiful sea salt collection. The wax blend, made by Cornwall-based artisanal candle brand Keynvor, is so refreshing and recalibrating. It’s a touch lemony and has some cool, aromatic herbs such as sage and fir needles in the mix, and along with a mellow woody base it radiates the most crisp, breezy and cleansing scent as it burns - as if you’ve seasoned your own home with a crunch of pinging sea salt.

It’s also only £28, it melts to the edges without tunnelling and the throw is excellent, which, as you can imagine, makes me a very happy bunny indeed.

Right, are we ready to make the best soup you’ll ever taste? Let’s get cooking!

On my Instagram I’ve posted a reel with the recipe in action, and here’s the full breakdown below:

KIT

• A large pan or casserole with a well-fitting lid. I use a very deep 28cm Greenpan sautée pan, and I’m seriously miffed I got a boring grey one in the sales and didn’t hold out for this dreamy sky blue one with brass fittings. For something less pricey, this one from John Lewis is about half the price.

• Swimming goggles

INGREDIENTS - makes enough for 6 people

• 10 medium or 8 large yellow onions, halved and finely sliced (wear your goggles for this bit!)

• Extra Virgin Olive Oil

• Cornish Sea Salt sea salt crystals

• Black pepper

• Nutmeg

• One heaped tablespoon of plain flour, toasted in a dry pan for 5 minutes (explained below!).

• A couple of knobs of butter

• A measure of brandy or cognac

• A medium glass of any red wine

• 2 litres of stock (I used 1l of chicken stock mixed with 1l of beef stock. You can use just vegetable stock too, or blend all three for a mixed stock)

• A splash of balsamic vinegar

• 200g Gruyère cheese, finely grated

• Baguette slices, halved if too big.

METHOD:

1. Sauté your onions

Heat up your pan on full whack and add enough olive oil to coat the bottom.

Add half the amount of sliced onions, keeping the rest for later.

Throw in a generous pinch of Cornish Sea Salt; this helps to soften the onion’s fibres and draw out any bitterness. I add a big knob of butter too, because I’m French like that.

Sauté for about 15 minutes until golden and slightly caramelised. Tip into a separate bowl and leave aside.

Repeat all these steps for the second batch of onions.

At this point you could leave them to cool and store the sautéed onions in a Tupperware to keep for later (or in the fridge for up to 3 days). Especially if you’re having friends over for dinner and you might not want an oniony smells coursing through your home. But then again, isn’t that the most delicious aroma ever? Sticky, sweet, buttery and nutty fried onions. Especially with the Sea Salt candle in the mix to add some freshness. Divine.

2. Prep the other bits

Get your 2 litres of stock ready. Up to you whether you want a mix of chicken and beef; a third each of veg / chicken / beef; or just chicken or veg on their own. I probably wouldn’t go beef stock on its own or the soup will become gravy (nice for two spoonfuls mind you, but too much as a bowl of soup).

Pour a shot of brandy or cognac into a mug or glass, and top it up with any red wine. No need for specific measures here; this type of cooking is about blurred edges and letting your instincts guide you. However if you’re unsure (I understand, my husband is a scientist and requires numbers), aim for 50ml of brandy and 250ml of red wine.

Prepare your toasted flour. This is a thickening trick for soups and gravy. Plain raw flour works fine too, but by toasting it you get rid of the raw flavour it adds a slightly nutty warmth when you cook with it. Put a heaped tablespoon of flour into a small, dry frying pan and place it on a medium heat. Using a wooden spoon, move it around frequently and WATCH IT LIKE A HAWK. Nothing will happen for a good 5-8 minutes, then suddenly it’ll start going brown. Turn off the heat when it’s the colour of pale cardboard.

3. Bring everything together

Heat the onions back up on the highest heat and pour in the booze. Let that fry off for about 2 or 3 minutes. I also throw in a big dash of Balsamic Vinegar, give it all a good stir and let the onions caramelise a bit more.

Pour in the stock and bring back to the boil.

Season well with Cornish Sea Salt, freshly ground black pepper and a few gratings of nutmeg.

Move your pan onto a smaller ring on your cooker, on the lowest heat possible. Place the lid on and leave to simmer away for 30 minutes.

4. Prepare your croutons

Traditionally, French Onion Soup is served in white porcelain lion-head bowls, with Gruyère croutons placed on top of the soup and straight into a grilling oven for 5 minutes to bubble up and go all crusty-delish. For me personally, this doesn’t work as the bowl becomes volcanic and I have kids who will 100% touch the bowl when asked not to (I actually do this too tbh, especially in a restaurant when I’m told explicitly that I must not touch the hot bowl or plate. Obviously I need to be the judge of that, pal). I also don’t own those bowls and instead use one my Uncle Michel in France made for me - he’s a potter who specialises in Chinese glazing techniques and although I’m sure they’d withstand a grill I don’t really fancy mopping up a ton of shattered china, stringy cheese and litres of hot onion soup from inside my oven. Instead, this is what I do:

Grate your Gruyère and set aside in a bowl.

Slice your baguette into small discs. Halve the bigger ones so that they’re easier to eat in one spectacular mouthful. Arrange these in one layer on a baking tray.

Top each piece of bread with a generous cluster of grated cheese.

Set aside until you’re ready to serve.

5. Time to dish up!

After the 30 minute simmer, remove the lid and have a taste of your soup. Season a touch more if necessary. It will probably be slightly on the thin side, so put your pan back onto the biggest ring and bring it back to a ferocious boil, lid off, for 15 minutes until reduced.

Ladle the soup into bowls and place all of your bowls on a safe, empty kitchen surface.

With a blowtorch, heat the cheesy croutons until melted and very slightly scorched (this is the smell of my childhood; blow-torched cheese baguettes made by my dad outside his tool shed, fusing the blend of sweet nutty cheese with a bitter, matchstick kick)

Using a small slotted turner or flat spatula, place your grilled cheesy croutons on top of the soup - I tend to put about 4 on each bowl.

Sprinkle any remaining cheese on top of each bowl, or bring it to the table for guests to help themselves to. There should be enough baguette leftover to make a few last-minute croutons for anyone wanting seconds. Which they will, trust me.

Serve with a big green salad and your Cornish Sea Salt candle on the table to elevate your senses and make all those incredible flavours ping around your tastebuds and nose.

Enjoy!

Thank you so much for subscribing to my Perfume Playground, I appreciate every single one of you here. The response to my previous foodie post was so positive - thank you! - so it’s a joy to bring a bit more of this personal passion onto my Substack.