1Preheat oven to 180°C.
2Slice the baby marrows, peppers and mushrooms finely.
3Place the mushrooms in a baking dish, sprinkle over the olive oil and add 1 tsp of butter to each mushroom.
4Place in the oven for 10 Minutes.
5In a pot add 1 tsp of olive oil, baby marrows, peppers and mushrooms and fry until browned for about 7 Minutes.
6Remove from heat.
7Add the baby marrow and mushroom mixture on top of the portabello mushrooms and sprinkle with shredded cheddar cheese.
8Place baking dish back in the oven and bake for 5 Minutes until cheese is melted and still soft.
9Sprinkle with salt and pepper to taste.