From Helen of Beyond Salmon
Butter for greasing the baking dish
4 medium Yukon gold potatoes
2 cloves garlic
1 1/2 teaspoon salt, divided
1/4 teaspoon black pepper, divided
2 teaspoons olive oil
¼ cup chopped parsley
4 tilapia or other firm white fillets
Set the racks in the bottom third and middle positions of your oven. Preheat the oven to 425F. Heavily butter a large shallow baking dish (about 10 by 16 inches).
Peel potatoes and slice into very thin (1/8" thick circles) using an adjustable blade slicer. Slice the garlic paper thin.
Mix potatoes, half of sliced garlic, olive oil 1 teaspoon salt, and 1/8 teaspoon pepper, and spread evenly in the baking dish in a single overlapping layer. Bake in the bottom third of the oven for 15 minutes or until potatoes are almost tender and starting to crisp around the edges of the baking dish.
Mix the remaining half of sliced garlic, parsley, 1/2 teaspoon salt and 1/8 teaspoon pepper in a large plate. Rub into fish fillets. Place fish fillets in a single layer on top of potatoes and bake in the middle of the oven 10 minutes per inch of thickness or until the fish is opaque in the center, but still juicy.
