Steak and Cheese Pasta

8 oz gemelli or rotelle pasta
2 cups milk
2 Tbsp cornstarch
1 Tbsp Dijon mustard
1/4 tsp paprika
1 cup shredded reduced-fat Cheddar cheese
1 1/2 cups reserved cooked sirloin steak, cut in narrow strips
1 cup reserved cooked onions, chopped
1 cup diced tomatoes, unsalted
Garnish: chopped parsley

Cook and drain pasta as package directs. Meanwhile whisk milk and cornstarch in a medium saucepan to blend. Bring to a boil over medium-high heat, stirring often. Whisk in mustard and paprika; simmer 1 minute or until thickened. Add cheese, steak and onions; stir until cheese melts. Remove from heat; toss with pasta. Top with the tomatoes; sprinkle with parsley.