4-5 medium/large Russet potatoes
1 1/2 c. water
4 T. butter (1/2 stick)
1 large yellow onion, sliced thinly
1 large leek, sliced thinly
4 cloves of garlic, minced
1 bunch of green onions, sliced
3/4 c. butter (1 1/2 sticks)
2/3 c. flour
1 T. salt
1 1/2 tsp garlic pepper
1 1/2 tsp dry mustard
5 c. milk
Wash and scrub the potatoes. Poke holes in each of them to keep them from exploding. In pressure cooker, place the trivet in bottom with 1 1/2 c. water. Place the potatoes on trivet. Bring water to boil. Secure the lid. Pressure at the second red ring for 8-10 minutes.
Allow pressure to drop on its own. Cool for 15 minutes, then peel if desired. If you don't have a pressure cooker, just boil the whole potatoes in water until they are semi cooked.
Using either a mandoline or a knife, slice the potatoes into 1/4" round slices.
Preheat oven to 350ºF.
In skillet, saute 4 T. butter (1/2 stick), onion slices, leek slices, garlic, green onions.
Set this saute mixture aside.
To make roux sauce:
Melt 3/4 c. butter (1 1/2 sticks) in a skillet. Mix together the flour, salt, garlic pepper, and dry mustard and add that mixture to the butter in the skillet. Slowly add 5 c. milk to butter mixture, stirring occasionally until thick.
Spray a casserole dish with pam. Alternate layers of the ingredients with sauce putting sauce in first (sauce, potatoes, sauce, onions, etc). Bake uncovered in 350º oven for 30 - 35 minutes (or until browned on top).
To cook on the BBQ, cover with foil, heat grill to 350º. Turn one side of the grill off. Place the casserole dish on non-heated side; bake for 25-30 minutes or until the potatoes are tender.