• 1 large cauliflower, broken into florets
• 6 tablespoons butter
• 1/4 cup flour
• 1 teaspoon salt
• 2 cups milk
• 2 tablespoons prepared mustard
• 1/2 cup soft bread crumbs
• 1/4 cup Parmesan cheese
Cook cauliflower in boiling salted water until just crisp-tender, about 6 minutes. Drain cauliflower and transfer to a lightly buttered 1 1/2-quart baking dish.
In a small saucepan, melt 3 tablespoons of butter; blend in flour and salt. Stir until smooth and bubbly. Gradually add milk, stirring constantly. Continue cooking and stirring until sauce is thickened and smooth, for about 3 minutes. Stir in mustard. Pour sauce over cauliflower in casserole.
Melt remaining butter in a medium saucepan; add bread crumbs and toss to coat. Sprinkle Parmesan cheese over casserole then top with buttered bread crumbs. Bake at 375° for 20 minutes, or until bubbly and browned.