Created by BusyMiz on April 19, 2013
Step 1: Preheat oven to 400 degrees F.
Step 2: In large saucepot, cook pasta in boiling salted water 5 minutes; add broccoli to pasta and cook another 5 minutes or until broccoli is tender and pasta is al dente. Drain well and return to saucepot; set aside.
Step 3: Meanwhile, in 3-quart saucepan, melt margarine or butter over low heat. Stir in flour, salt, pepper and garlic powder until blended and cook, stirring, 1 minute.
Step 4: Gradually stir in milk; increase heat to medium-high and cook, stirring occasionally, until mixture thickens and boils. Boil 1 minute, stirring frequently. Remove saucepan from heat and stir in 1/2 cup Swiss cheese until blended.
Step 5: Add cheese sauce and tuna to pasta and broccoli in saucepot; toss until evenly mixed.
Step 6: Transfer mixture to greased shallow 3 1/2-quart casserole or 13-inch by 9-inch glass baking dish.
Step 7: Arrange tomato slices on top, overlapping if necessary.
Step 8: Sprinkle with remaining 1/2 cup Swiss cheese.
Step 9: Cover baking dish with foil and bake 20 minutes or until hot and bubbly.