spicy cajun chicken and penne pasta

Ingredients

• 2 cups chicken, cooked
• 2 jars alfredo sauce,15 ounces each
• 1 medium onion,peeled, chopped
• 1/2 cup mushrooms,chopped
• 1 medium green bell pepper, chopped
• 1 teaspoon garlic powder
• 1 cup milk
• 1/2 cup parmesan cheese
• 1 cup salsa, chunky
• 1 tablespoon cajun seasoning, or to taste
• 2 dashes red pepper flakes,or to taste
• 2 dashes salt and pepper,or to taste
• 2 tablespoons margarine,or butter
• 8 cups penne pasta,cooked and drained