Potato and Onion Tart (adapted slightly from Hizzoners Deli)
2 tablespoons butter
about a teaspoon of fresh thyme leaves
1 large onion, sliced a litle more than 1/4 inch thick (we like sweet onions for this)
1 lb red potatoes, washed and sliced very thin
2 tablespoons olive oil
1/2 cup shredded Gruyère cheese
1/2 cup crumbled feta
1 cup shredded mozzarella (don't use preshredded!)
kosher salt and black pepper
Preheat your oven to 400°. Start heating an oven-safe skillet (like cast iron!) over medium-high heat. Place the butter in to melt. Place the onion slices in a single layer over the melted butter, cut side down. Cook for 5-8 minutes, till the onions are softened. Combine the potatoes, oil, cheeses, salt and pepper in a bowl stir till evenly distributed and coated.
Pour the potato mixture over the onions, spread evenly, and bake for 45 minutes or until golden brown and cooked through. Turn upside down to serve...