Sweet Pea Casserole Recipe

Preheat oven to 350°, lightly grease 9x13 in baking dish. In a Dutch oven, melt butter over medium heat. Add mushrooms, onion, and garlic; cook for 5-6 minutes or until tender. Stir in flour, sugar, salt, pepper, and nutmeg; cook stirring constantly for 2 minutes. Reduce heat to medium-low; gradually stir in half and half, and cook for 6-8 minutes stirring constantly, or until slightly thickened. Add cheeses, stirring until melted and smooth. Add peas, stirring to combine. Spoon mixture into prepared baking dish; bake for 45 to 50 minutes. Top evenly with French fried onion and bake for 5 minutes longer; serve immediately.