The best French onion grilled cheese sandwich 

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The best French onion grilled cheese sandwich in a frying pan

If you love French onion soup (this is my best French onion soup recipe ever) and a good grilled cheese toastie, you will love this French onion soup grilled cheese sandwich. While sandwiches are typically assembled quickly with a few ingredients for a convenient lunch, I personally enjoy going above and beyond to create something truly extraordinary.

Onions and cheese fro a French onion grilled cheese recipe

Onions are slowly braised in brown butter, bay leaves and thyme to make an unctuous base for this grilled cheese sandwich. Redolent of French onion soup this sourdough toasted sandwich is so delicious and worth the little effort.

Mix the cheese with the onions before the sandwich is assembled. This technique guarantees a uniform melting of the cheese, and each mouthful has the perfect ratio of cheese and jammy onions. 

Sage leaves on slices of sourdough for a French onion grilled cheese

I have used La Motte sourdough bread which is simply perfect. Made in an ancient way in a woodfired oven on the farm, this robust bread provides the perfect structure to contain the rich onion and cheese filling.

Making a good grilled cheese is getting the balance right between thoroughly heating and melting the filling without over-browning the bread. This can happen if the pan is too hot. It’s best to err on the side of caution and toast it over medium to medium-low heat. If necessary, you can crank up the heat if necessary to get the level of browning and crunch that you want.

French onion grilled cheese sandwich in a frying pan

The best French onion grilled cheese sandwich 

About La Motte Bakery & Bread:

La Motte owners and acclaimed baker Markus Farbinger (founder of Knysna’s Île de Pain) have created a casual and inviting artisan bakery and café pâtisserie in Franschhoek. The breakfast and light lunch menu offer delicious and accessible options, including freshly baked bread from the wood-fired oven. You can also purchase loaves and sweet treats to take home. Located in the historic Jonkershuis, the café has a terrace and overlooks gardens, oak trees, and a farmyard-inspired playground, making it a family-friendly destination.

I was thrilled to be able to collaborate with this beautiful farm to produce a few recipes that showcase their delicious bread. You can see the three healthy tartines I made using their ciabatta, wholewheat and sourdough.

A loaf of sourdough b read to make the best French onion grilled cheese sandwich 

This French onion grilled cheese sandwich recipe was inspired by the upcoming Bastille Day celebrations in Franschhoek. Check out my Instagram post for the lovely giveaway La Motte is doing. 

This grilled cheese pairs perfectly with the La Motte Rosé Vin de Joie.

The best French onion grilled cheese sandwich served in a pan

Tips to make a perfect grilled cheese sandwich.

You can add so many fillings to your grilled cheese but here are a few tips on how to make a perfect one:

  1. First, choose the right bread. Opt for sturdy bread like sourdough or dense white bread, as this will hold up well to the heat and maintain a good texture. 
  2. Next, if you are using only cheese, use a combination of cheeses for depth of flavour and gooeyness. Experiment with different types such as cheddar, mozzarella, mature Gouda, Dalewood Fromage Huguenot or Boland, or Gruyere. 
  3. Butter the outer sides of the bread generously for a crispy and golden crust. Or spread mayonnaise on the outside (this will crisp up the bread in a similar way). 
  4. Preheat the pan or griddle over medium heat to ensure even cooking and melting of the cheese. Place a lid over the sandwich as it cooks to trap heat and encourage thorough melting. 
  5. Flip the sandwich only once, allowing each side to become beautifully golden. 
  6. Finally, allow the grilled cheese to rest for a minute before cutting it. This allows the cheese to set and prevents it from oozing out. By following these tips, you’ll be on your way to creating the perfect grilled cheese sandwich every time.
The best French onion grilled cheese sandwich 

More delicious recipes paired with La Motte Wine:

Creamy salmon pasta with spinach & capers

Roast baby chickens with pork, pistachio & cranberry stuffing

Whole baked trout with herbs and lemon

A bottle of La Motte Vin de Joie Rosé 

My best-toasted sandwiches

Giant grilled cheese with hot honey butter

Classic South African braaibroodjie jaffles

Toasted Cheddar cheese sandwich with buttery leeks

Jalapeno popper grilled cheese sandwich with bacon

Caramelised pear and Gorgonzola toasties

Recipes – serves 2

The best French onion grilled cheese sandwich 

This sandwich captures the essence of a French onion soup to make the most delicious and decadent grilled cheese. 
Print Recipe
The best French onion grilled cheese sandwich 
Prep Time:10 minutes
Cook Time:30 minutes


  •  3 White or brown onions peeled, halved, and cut into thinnish slices
  • 30 gm salted butter + more for spreading on the bread
  • 2 bay leaves
  • 3 tsp thyme leaves
  • 3 – 4 Tbs medium of pale-dry sherry optional
  • ¼ cup – 1/3 cup onion stock or veg stock to use if necessary and to deglaze the pan
  • 90-100 gms Dalewood Fromage Huguenot Gruyere, very mature Cheddar or Gouda, grated
  • 1 tsp sherry or red wine vinegar
  • 4 slices of La Motte sourdough bread
  • 4 sage leaves optional
  • Salt and black pepper


  • To make the filling, slice the onions and then heat a large non-stick pan over medium-low heat.
  • Add the butter and allow it to brown. This will give the onions a slightly nutty flavour.
  • Add the onions along with the bay leaves and fresh thyme and then season with salt and pepper. Turn the heat down to low.
  • Once the onions have softened and started to take on some colour (this will take about 10-15 minutes), add the sherry if you are using it and put a lid on the pan. Continue to cook them for another 10 – 15 minutes. Stir occasionally. If necessary, add a splash of the onion stock to deglaze the pan and prevent sticking.
  • Once the onions are nice and golden, remove the lid, and add a splash more stock. Allow them to cook until very golden brown, and sticky. The process to caramelize onion takes at least half an hour, but this part can be made in advance.
  • Decant the onions to a bowl to cool and remove the bay leaves.
  • Once the onions have cooled slightly, add the grated cheese, and sherry (or red wine) vinegar and stir to combine.
  • Butter one side of each slice of bread. Dived the onion and cheese mixture into 2 and spread it thickly onto two of slices of sourdough. Ensure the buttered sides are on the outside.
  • If you are using them, press 2 sage leaves into one side of each sandwich (this is optional).
  • Fry the sandwiches in a large skillet over medium to low heat until golden and toasted and the filling is warm and melty. They should take around 3 – 4 minutes per side and keep a close eye to prevent the bread from going too dark before the cheese has melted.
  • Alternatively, toast the sandwiches on a sandwich press or in an air fryer too.
  • Once the sandwich is a deep golden brown colour, allow it to rest for a minute then slice and enjoy.


The filling can be made in advance and kept in the fridge until ready to toast the sandwich.
Servings: 2
Author: Sam Linsell

* This post is proudly sponsored by La Motte


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