This creamy casserole is as close to comfort food as you can get with no canned ingredients! It does take some effort to make, but it's worth it. You can also change this recipe into an amazing turkey tetrazzini casserole by swapping out the tuna.
Preparation Time
20 mins
Cooking Time
50 mins
Total Time
1 hr 10 mins
Calories
655 Calories
Recipe Instructions
Step 1
Preheat the oven to 350 degrees F (175 degrees C). Lightly oil an ovenproof skillet and an 8x12-inch casserole dish.
Step 2
Place tuna in the prepared skillet and bake in the preheated oven until fish flakes easily with a fork, 8 to 10 minutes.
Step 3
Fill a large saucepan with lightly salted water and bring to a rolling boil. Cook fettuccine at a boil until tender yet firm to the bite, about 8 minutes. Drain and set aside.
Step 4
Remove tuna from the oven; leave oven on.
Step 5
Meanwhile, melt 3 tablespoons butter in a saucepan over medium heat. Cook onion and mushrooms until softened, stirring occasionally, 5 to 7 minutes. Stir in flour until blended. Add milk, bouillon concentrate, adobo seasoning, and black pepper. Cook, stirring constantly, until mixture is slightly thickened, about 5 minutes more. Remove sauce from heat and stir in Parmesan cheese.
Step 6
Place remaining butter in a medium-sized microwave-safe bowl and heat in the microwave until melted, about 30 seconds. Stir bread crumbs into melted butter and set aside.
Step 7
Add cooked fettuccine and flaked tuna to the cheese sauce and toss to combine. Transfer noodle mixture to the prepared casserole dish and top with torn bread.
Step 8
Bake in the hot oven until golden brown, about 20 minutes.
Ingredients
6 tablespoons butter, divided
¼ cup grated Parmesan cheese
¼ teaspoon black pepper
1 medium onion, diced
2 ¾ cups milk
¼ cup flour
2 (5 ounce) tuna steaks
½ teaspoon adobo seasoning
8 ounces fettuccine noodles
6 ounces sliced portobello mushrooms
1 teaspoon chicken bouillon concentrate (such as Better than Bouillon®)