The croque madame is my favourite take on the humble cheese toastie, and the twists here add a real depth of flavour. Cumin seeds, turmeric and caramelised shallots spice up the classic cheese sauce, which I like to fire up further with a handful of chopped green chillies. While the classic madame is topped with a fried egg, I prefer poached Freshlay Farms Golden Yolker eggs - something about their golden yolks dripping over crispy cheese makes my heart sing, and takes this dish to the next level.
Toast your sourdough bread and switch on your grill to medium. While it warms, heat a medium-sized saucepan over medium heat, add the butter and melt. Tip in the cumin seeds and wait until they start to sizzle. Add the sliced shallot and green chillies, with a pinch of salt and black pepper, and cook for 4-5 minutes or until softened. Then add the turmeric and plain flour, mixing really well to form a paste. Cook for a further 30 seconds and remove from the heat.
Gradually pour in the milk, again mixing well to prevent lumps. Once all the milk is added, return the pan to a medium heat and cook, stirring all the time, for 3-4 minutes or until the sauce has thickened to a double cream consistency. Finally, stir in a third of the grated gruyère and mozzarella - this is your green chilli cheese sauce.
Line a baking tray with non-stick baking paper, and lay two slices of toast on to it. Spoon a quarter of the sauce over each slice, then add the ham and sprinkle on another third of both cheeses. Top with the remaining slices of toast.
Spread the rest of the cheese sauce on top of the sandwiches and finish with the last of the gruyère and mozzarella. Grill for 3-4 minutes or until the cheese is bubbling and browned. While the toastie is grilling, poach the eggs. Half fill a saucepan with salted water and bring to the boil. Crack each egg into a separate small jug or bowl. Swirl the water to create a mini whirlpool, then carefully slip the eggs into the moving water, one after the other. Cook for three minutes, then scoop out and drain on kitchen paper.
Pop the eggs on top of the sizzling cheese, sprinkle with fresh chives and serve with green leaves on the side. Dress, if you like, with olive oil.