New england broccoli cheese soup recipe

Ingredients

• 2 tablespoons onion
• 2 tablespoons margarine
• 3 tablespoons flour
• salt and pepper to taste
• 2 cups whole milk or half and half
• 1 1/4 cups shredded sharp Cheddar cheese
• 2 chicken bouillon cubes
• 1 1/2 cups water
• 20 ounces frozen chopped broccoli
• 1 cup cooked chicken (optional)