- 4 tablespoons oil or butter
- 4 tablespoons flour
- 1 teaspoon salt
- 1/2 teaspoon white pepper
- 1/2 teaspoon dry mustard
- 1 3/4 cup low-fat milk
- 1/2 cup grated white cheddar, or Emmenthal cheese, or other good quality cheese (cheese is optional if you are watching your fat intake)
- 3 russet baking potatoes, peeled and sliced
- 1 sweet potato, peeled and sliced
- 1 leek or onion, trimmed and sliced
- 2 tablespoons grated Parmigiano-Reggiano cheese
Preheat the oven to 350 degrees.
In a batter bowl, combine the butter and flour. Microwave on high for 30 seconds, and then whisk in the salt, pepper, mustard, and milk. Microwave on high for 2 minutes. Whisk well. Microwave another 1-2 minutes, or until thickened. Whisk in the cheese and set aside.
In a buttered casserole, arrange the slices of potatoes and the leeks, drizzling a little of the sauce between the layers, ending with the rest of the sauce. Sprinkle with the cheese. Bake, uncovered, at 350 degrees for 45-50 minutes or until the potatoes are tender.
Or, to speed things along, assemble the casserole but do not put the Parmigiano cheese on the top. Cover with plastic wrap and microwave on high for 10 minutes. Then remove the plastic wrap, sprinkle on the cheese and slip into the hot oven to finish baking for about 20 minutes.
- Yields: 1 large casserole
- Preparation Time: 1 hour and 45 minutes