Preheat oven to 350°. Heat a large skillet over medium heat. Add oil and onion. Sauté for 5 minutes, add beer and then cook 12 more minutes or until liquid evaporates, stirring occasionally. Remove onion mixture from heat and set aside.

Cook potato slices in boiling water for 8 minutes or until crisp-tender, then drain. Rinse under cold water and drain well. Place one third of the potato slices in an 11 x 7-inch baking dish coated with cooking spray. Sprinkle potato layer with half of the salt and half of the pepper.

Spread half of the onion mixture over potato slices. Repeat procedure with another one third of the remaining potato slices, and the rest of the salt, pepper, and onion mixture. Top the dish with remaining potato slices. In a small bowl, add cornstarch and a small amount of milk. Whisk until smooth. Pour cornstarch and milk into the rest of the milk and whisk again. Pour milk mixture evenly over potato slices. Cover with aluminum foil. Cut 3 short slits in foil.

Bake at 350° for 45 minutes. Uncover, sprinkle with cheese and then bake an additional 10 minutes or until cheese melts.

Prep Time: 15 minutes
Inactive Prep Time: 0 minutes
Cook Time: 1 hour 15 minutes

This recipe may appear slightly modified from what you've seen on television.