Greek Chicken Spaghetti

Greek Chicken Spaghetti
6 chicken breasts
Salt to taste
1 large onion, chopped
1 large bell pepper, chopped
1/2 cup (1 stick) margarine
1 (4-oz.) can sliced black olives, drained
1 (28-oz.) can tomatoes, chopped
1 (4-oz.) jar mushrooms, drained
2 cups chicken broth
2 1/2 Tbsp. Greek seasoning
8 oz. feta cheese, crumbled
1 cup (4 oz.) shredded sharp Cheddar cheese
1 lb. spaghetti, cooked and drained
Cook chicken in enough salted water to cover in a saucepan until cooked through; drain. Chop chicken; discard skin and bones. Saute onion and bell pepper in margarine in a skillet until onion is translucent. Combine chicken, sauteed vegetables, olives, undrained tomatoes, mushrooms, chicken broth and Greek seasoning in a large bowl and mix well. Add feta cheese, Cheddar cheese and spaghetti, and toss.