Baked Macaroni with Zucchini and 3 Cheeses

1 pound elbow macaroni
6 tbsp butter, plus more if needed
1 tbsp olive oil
2 medium zucchini, trimmed and neatly sliced
1-1/2 cups sliced mushrooms (5 ounces)
1 medium - large onion, coarsely chopped
1 medium pepper, red or green, diced
2 cloves of garlic, minced
1/4 cup flour 1 quart cold milk
1 tsp salt
1/4 tsp nutmeg
1/2 cup sour cream
1 tsp Worcestershire sauce
few drops of hot sauce (optional)
1-1/2 cups grated sharp cheddar cheese
1-1/4 cups grated Swiss cheese
1/2 cup grated Parmesan cheese

Preheat the oven to 400 degrees, cook macaroni until al dente (8 minutes). Drain, rinse and set aside. In a skillet heat 2 tbsp of butter with the olive oil, add the zucchini and the mushrooms, sauté for 5 minutes, transfer to a plate. Again in the skillet, add 3 tbsp of butter and sauté the onion, pepper, and garlic. Cook until soft, not brown (8 minutes). Sprinkle the veggies in the skillet with the flour and still until the flour is opaque, you may need to add a little more butter. This may take up to four minutes. Add the milk to the skillet, bring to a boil, stirring occasionally. Add the salt and nutmeg, simmer for 5 minutes. Remove from the heat, stir in the sour cream, Worcestershire sauce and the hot sauce, put aside. In the pot you cooked the macaroni, put back the macaroni, the zucchini mixture, the cheddar and Swiss cheese, the sauce and 1/4 cup of the Parmesan cheese. Mix together and put into a buttered 9 x 13 pan, sprinkle with remaining cheese and dot with remaining butter, bake 45 minutes, until crusty.