Broccoli-Cheddar Puff

INGREDIENTS
6 tbls butter or margarine
6 tbls all-purpose flour
1/2 tsp salt
1/8 tsp ground red pepper (cayenne)
2 1/4 cup whole milk
2 cups shredded sharp Cheddar cheese
4 head broccoli
1 head cauliflower
7 large eggs, separated
½ lb bacon, chopped
small onion, chopped
DIRECTIONS
1. Fry up bacon and onion, crisp
2. Chop up broccoli and cauliflower into bite-sized chunks, and in stir bacon and onion mixture; place into your greased casserole dish (should comfortably fit, with some headroom for the puff)
3. Melt butter in a large saucepan; and flour, sauté on low heat for a minute or so, to cook out the floury taste, add salt and pepper.
4.Gradually stir in milk, cooking until it boils and thickens, stirring often. Lower heat, and add cheese stirring just until it melts; remove from heat.
5. In small bowl, with fork, lightly beat egg yolks. Stir in about 1/2 cup cheese sauce. Gradually pour egg-yolk mixture into cheese sauce, stirring rapidly to prevent curdling. Cool slightly; meanwhile, preheat oven to 325º F.
6. In large bowl, with mixer at high speed, beat egg whites until stiff peaks form when beaters are lifted. With rubber spatula, gently fold one third of whites into cheese mixture. Fold cheese mixture gently back into remaining whites.
5. Pour sauce over veggies into prepared casserole. Bake 40 minutes or until top is browned and knife inserted in center comes out clean. Serve immediately.