Croque Candied Red Onions & Cheddar Sandwich

Rich, savoury, and slightly sweet, the Croque Candied Red Onions & Cheddar Sandwich is a gourmet twist on the classic French croque. It combines deeply caramelised red onions, sharp cheddar cheese, and golden toasted bread for a sandwich that is crispy on the outside and irresistibly melty inside.

Croque Candied Red Onions & Cheddar sandwish – Delightful Meal

Print Recipe

Pin Recipe

Ingredients

4 slices of country bread (240 g)

ges 200 grams of red onions

180g of grated refined cheddar

120 g of grated mozzarella

x 25 g of soft butter

‘ 10 ml of olive oil

10 g of honey

3 grams of salt

2 g ground black pepper

1 g of dried thyme

Instructions

1 Slicing the onions

Peel the red onions and then cut them into thin, regular slices so that they cook evenly.

ons Melt the onions

Heat the olive oil in a skillet over medium heat. Add the red onions and let them cook for 8 minutes, stirring regularly.

Confire the filling

Add honey, thyme, salt and pepper. Continue cooking for 4 to 5 minutes until the onions become tender, shiny and slightly caramelized.

Prep the cheeses

Mix grated cheddar and mozzarella in a salad bowl to achieve a rich texture and taste.

up the crumbs

Lay down two slices of bread on the worktop. Spread a layer of the cheese mixture onto each slice.

les Add the candied onions

Drop the caramelized red onions over the cheese by spreading them evenly across the surface.

Finish the topping

Add the rest of the cheese mixture onto the onions for an ultra flowing heart when baking.

Close up the crumbs

Cover with the remaining two slices of bread then press slightly.

l Butter the outside

Spread the butter on the outer surfaces of the croissants to achieve a nice golden and crispy crust.

Cooking the crocs

Heat a skillet over medium heat. Cook the crocs for 4 to 5 minutes on one side until they are well toasted.

Turn around and finish baking

Gently roll over the crusts and continue to bake for an additional 4 minutes until cheese is completely melted.

Serve

Let it rest for 1 minute before cutting in half. Enjoy immediately while the cheese is still running.

Tip to make the recipe easier

. Prepare a large amount of candied onions in advance and store them in the refrigerator for up to 4 days to make your croissants in minutes.

An ingredient to swap

Replace honey with maple syrup for a slightly woody note that pairs perfectly with cheddar.

Cooking hack

• Author: mia recipe

Perfect for brunch, lunch, or a comforting café-style meal at home, this sandwich delivers bold flavour with a beautiful balance of sweet and savoury notes.

Understanding the Perfect Croque Candied Red Onions & Cheddar Sandwich

Why This Recipe Is So Popular

This sandwich is loved because it is:

• Crispy and golden
• Sweet and savoury
• Rich and cheesy
• Simple yet gourmet
• Perfect for brunch or lunch

It elevates everyday ingredients into something special.

The Role of Cheddar Cheese

Cheddar provides:

• Sharp, tangy flavour
• Excellent melting quality
• Creamy texture when heated
• Rich savoury depth

It forms the cheesy core of the sandwich.

Why Candied Red Onions Are Essential

Candied red onions add:

• Natural sweetness
• Deep caramelised flavour
• Soft jam-like texture
• Beautiful contrast to the cheese

They are the flavour highlight of the sandwich.

The Importance of Bread

The bread contributes:

• Crisp toasted exterior
• Soft interior
• Structural support
• Golden buttery finish

It holds the filling while adding crunch.

The Role of Butter or Bechamel (Optional)

Butter or béchamel sauce adds:

• Richness
• Moisture
• Traditional croque texture
• Extra indulgence

It helps create a classic French-style finish.

Why Texture Matters

A perfect croque-style sandwich should include:

• Crunchy toasted bread
• Gooey melted cheddar
• Soft, sticky onions
• Slight crisp edges

This contrast makes every bite satisfying.

Optional Add-Ins

You can customise the sandwich with:

• Dijon mustard
• Fresh thyme
• Gruyère cheese
• Rocket (arugula)
• Ham (for a non-vegetarian version)

These add depth and variation.

The Role of Caramelisation

Slow-cooked onions provide:

• Rich sweetness
• Deep golden colour
• Complex flavour
• Sticky texture

This is what makes the sandwich stand out.

Perfect Occasions for Serving

Croque Candied Red Onions & Cheddar Sandwich is ideal for:

• Brunch menus
• Light lunches
• Café-style meals
• Comfort food cravings
• Weekend cooking

It feels both rustic and refined.

Nutritional Overview

This sandwich provides:

• Carbohydrates from bread
• Fat and protein from cheese
• Natural sugars from onions
• Satisfying energy

It is rich and comforting.

Preparing Before Cooking

Before starting:

• Slice red onions
• Prepare caramelisation ingredients
• Grate cheddar cheese
• Butter bread slices
• Preheat pan or oven

Preparation ensures smooth assembly.

What You’ll Learn in Part 2

Next, you’ll learn how to:

• Caramelise the red onions perfectly
• Assemble the sandwich layers
• Grill or toast until golden
• Achieve a gooey, café-style finish

Croque Candied Red Onions & Cheddar Sandwich 

Cooking and Assembling the Sandwich

Now it’s time to caramelise the red onions, layer the cheddar, and grill everything into a golden, melty croque-style sandwich. The result is a rich, sweet-savoury toastie with deep flavour and a crisp exterior.

Ingredients

For the Candied Red Onions

• 2 large red onions, thinly sliced
• 2 tbsp butter
• 1 tbsp olive oil
• 1 tbsp brown sugar
• 1–2 tbsp balsamic vinegar
• ½ tsp salt
• ¼ tsp black pepper

For the Sandwich

• 4 slices sourdough or rustic bread
• 2 cups grated sharp cheddar cheese
• 1 tbsp Dijon mustard (optional)
• 2 tbsp butter (for grilling)

Optional Add-Ins

• Fresh thyme leaves
• Rocket (arugula)
• Gruyère cheese (mixed with cheddar)

Caramelise the Red Onions

Heat a pan over medium-low heat.

Add:

• Butter
• Olive oil
• Sliced red onions

Cook slowly for 15–20 minutes, stirring often.

Candy the Onions

Once onions soften and turn golden, add:

• Brown sugar
• Balsamic vinegar
• Salt
• Black pepper

Continue cooking for 5–8 minutes until onions become:

• Sticky
• Deep golden brown
• Jam-like in texture

Remove from heat and set aside.

Prepare the Bread

Lightly butter the outside of each bread slice.

This helps create a crisp, golden crust when grilled.

Assemble the First Layer

Place two slices of bread on a flat surface.

Spread a thin layer of Dijon mustard (optional) for extra tang.

Add the Cheese

Add a generous layer of grated cheddar (or cheddar + Gruyère mix).

Make sure the cheese covers the bread evenly.

Add Candied Onions

Spoon a layer of candied red onions over the cheese.

Spread evenly for balanced flavour.

Finish with More Cheese

Add another layer of cheddar on top of the onions.

This helps bind the sandwich when melted.

Close the Sandwich

Top with the second slice of bread.

Press gently to hold everything together.

Grill the Sandwich

Heat a pan or grill pan over medium heat.

Cook the sandwich for 3–4 minutes per side, pressing lightly.

It should become:

• Golden brown
• Crispy on the outside
• Melted and gooey inside

Rest and Slice

Let the sandwich rest for 1–2 minutes before cutting.

Slice diagonally for a café-style presentation.

Serving Suggestions

This croque-style sandwich pairs well with:

• Tomato soup
• Green salad with vinaigrette
• Pickles
• Roasted vegetables
• Crispy fries

Pro Tips for Best Results

• Cook onions slowly for best sweetness
• Don’t rush caramelisation
• Use freshly grated cheddar for better melting
• Grill on medium heat to avoid burning
• Press lightly, not too hard

What the Finished Sandwich Should Be Like

Perfect Croque Candied Red Onions & Cheddar Sandwich should be:

• Crisp and buttery outside
• Gooey and cheesy inside
• Sweet from caramelised onions
• Sharp from cheddar
• Rich and deeply flavourful