8 oz. small shell pasta, cooked as directed
2 tbsp. each butter and flour
1 1/4 c. milk
2 1/2 c. grated Cheddar cheese
2 oz. ham cut in thin strips or chunks
1/2 c. scallions
Salt and freshly ground pepper to taste

Heat oven to 350 degrees. In small saucepan, melt butter over medium heat and add flour. Cook, stirring 2 minutes. Add milk and cook, stirring until thickened. Add 1 cup cheese. Combine cheese sauce with cooked shells, 1 cup cheese, ham and scallion. Place in one large or a few smaller casseroles. Top with remaining cheese; bake until browned and bubbly, about 10 minutes.