In a large skillet on medium heat, put 1 tbsp butter and 1 tbsp extra virgin olive oil. Add sliced mushrooms and cook until the water is released and cooked off, 2 minutes.
Add diced onion, peppers, garlic and thyme. Cook until tender, 6 minutes or so. Remove from heat and place in a bowl big enough for all the ingredients.
In the same skillet, heat 2 tbsp butter and whisk in the flour. Keep whisking for a minute or two to cook the flour.
Slowly add the cream and broth, whisking constantly to keep from lumping. Turn burner to high and whisk until the mixture thickens, 8 to 10 minutes.
Once thickened, add white sauce, corn, parsley and al dente pasta to the vegetables, (and ham slices if desired).
Mix all this together then place in a casserole dish which has been buttered with about 1 tbsp butter.
In a small bowl, mix bread crumbs and grated cheese and combine by hand until mixed. Sprinkle over the "Hot Dish" and place in pre-heated 400 degree oven until the cheese is melted and browned, (25 to 35 minutes).