1 large cauliflower, cut into florets
1/4 cup grated Parmesan cheese
1/4 cup flour
6 tablespoons butter
2 cups milk
1/2 cup soft breadcrumbs
2 tablespoons prepared mustard
1 teaspoon salt
Cook the cauliflower in boiling water for about 6 minutes (until crisp tender).
Drain and transfer the cauliflower to a lightly buttered 1 1/2 quart baking dish.
In a small saucepan, melt 3 tablespoons of butter and whisk in the flour and salt.
Stir until bubbly, then gradually add the milk, stirring constantly for about 3 minutes (until thick and smooth).
Stir in the mustard and pour the sauce over the cauliflower in the baking dish.
Melt the remaining butter, add the breadcrumbs and toss to coat.
Sprinkle Parmesan cheese over the casserole, then top with the buttered bread crumbs.
Bake at 375° F for about 20 minutes (or until bubbly and brown).