How to Make
Preheat oven to 115⁰C.
On a baking sheet toss sliced mushrooms and onion in olive oil. Sprinkle with a pinch of salt and pepper.
Bake in oven for 20 minutes or until roasted.
On one slice of bread, layer gouda, roasted mushrooms and onions, spinach, then more gouda.
Top with the other slice of bread.
In a skillet, melt butter over medium heat.
Place sandwiche for 2 minutes until lightly browned, then gently flip it. Cook for another 2 minutes, until cheese is melted and sandwich is browned.