Pasta, Chicken and Tomatoes

1 lb chicken breast meat, cooked and cut into cubes
1 lb of rotini or rotelle pasta, cooked al dente (do not overcook)
2 medium tomatoes, diced
1 14 oz can tomato puree
1 tbsp tomato paste
1 tsp crushed rosemary
1 green bell pepper, chopped
1 red bell pepper, chopped
1 cup sliced mushrooms
1 medium onion, chopped fine
1 clove garlic, minced
Olive oil
Salt, pepper
Grated parmesan cheese

Sautee garlic and onion in olive oil in a large skillet or dutch oven.  Add peppers, sautee 5 min. Add mushrooms, sautee another 5 min.  Add tomatoes, tomato puree, salt, pepper, rosemary, bring to boil and simmer 15 min.  Preheat oven to 450F.  Remove heat, and add chicken and pasta.  Stir well, then transfer to 9 by 13 baking dish.  Coat top liberally with parmesan cheese.  Bake for 10 min at 450F, then reduce heat to 375F.  Cook 40 minutes or until cheese turns golden brown.