Preheat oven to 375°F and grease a 9x13 inch baking dish.
Boil egg noodles until slightly undercooked; drain.
Sauté onion and garlic in butter until fragrant.
Stir in cream of mushroom soup, sour cream, and milk.
Add seasonings and simmer for 2 minutes.
Fold in tuna, peas, and half the cheese.
Combine noodles with sauce; mix well.
Pour into dish and top with remaining cheese and breadcrumb mix.
Bake 25–30 minutes until golden and bubbly.
Rest 5 minutes before serving.