1 1/2 tbsp extra virgin olive oil
250g Swiss Brown Button mushrooms (about 4), thinly sliced into rounds
100g unsalted butter
1 French shallot, finely diced
2 garlic cloves, finely chopped
2 tsp thyme leaves
4 slices crusty white bread
1 tbsp Dijon mustard
50 g cheddar cheese, thinly sliced
50 g fresh mozzarella, thinly sliced
Tomato sauce, to serve (optional)
Preheat a sandwich press, if you have one.
Heat the oil in a large frying pan over high heat, add the mushrooms and cook until they have released their water and started to colour.
Turn the heat to low, add half the butter, then all of the shallots, garlic and thyme and continue cooking until the mushrooms are cooked through and the butter has started to brown. Check the seasoning. Remove the pan from the heat and place to one side.
Thinly spread the mustard onto one side of the slices of bread. Lay the cheddar slices on top of half of the slices, spoon on the mushroom mixture, then finish with the mozzarella slices. Sandwich with the remaining bread slices.
If using a sandwich press, melt the remaining butter and brush on the both sides of each sandwich. Cut in half to serve.