Tuna Noodle Casserole

Name: Tuna Noodle Casserole
Prep time: 10 min
Cook time: 55 min
Total time: 1 h 5 min
Cuisine: American
Ingredients: 1 yellow onion, diced ($0.78); 4 Tbsp butter, divided ($0.49); 8 oz. mushrooms, sliced ($2.18); 3/4 tsp salt, divided ($0.04); 1/4 tsp pepper ($0.03); 2 Tbsp all-purpose flour ($0.02); 2 cups whole milk ($0.37); 1 cup vegetable or chicken broth ($0.09); 4 oz. cream cheese ($0.88); 1/2 cup frozen peas ($0.25); 8 oz. wide egg noodles ($0.74); 2 Tbsp breadcrumbs* ($0.04); 2 Tbsp grated Parmesan ($0.18); 12 oz. chunk light tuna, drained** ($2.06)