In a medium pot, cook the pasta according to the package directions.
8 ounces pasta
In a large pot on the stove top, melt 2 tablespoons butter over medium heat.
4 tablespoons butter
Once the butter is completely melted, sauté the onions until clear and tender. This should take about four minutes.
1 medium onion
Once the onions are tender, add the sliced mushrooms and cook until your desired texture is reached. About four minutes for tender mushrooms.
1 cup sliced mushrooms
Place the onions and mushrooms in a small bowl and set aside.
Add the remaining 2 tablespoons of butter to the pot and melt it.
4 tablespoons butter
Once melted, whisk the flour into the butter to make a roux.
¼ cup all-purpose flour
Allow the roux to bubble and then whisk in the milk.
2 cups milk
Season the cream sauce with salt, pepper, and thyme and then allow it to simmer for 8 minutes or until thickened.
salt and pepper, 1 teaspoon thyme
Slowly stir in the chicken broth.
½ cup chicken broth
Add the pasta, green peas, and cooked ham until ingredients are warm and thoroughly coated in the sauce.
8 ounces pasta, 1 cup green peas, 2 cups cooked ham
Turn the oven on broil.
Pour the pasta mixture into an 8x8 casserole dish, and sprinkle the top with grated parmesan cheese. Broil for about 2 minutes or until the cheese is golden brown.
¼ cup grated Parmesan cheese
Serve this pasta dish in a bowl or on a plate and enjoy your meal.