Upside Down Potato & Onion Tart

• 2 1/2 tablespoons butter
• 12 sprigs thyme, strip the leaves from the stems
• 1 large onion, sliced somewhat thickly (a tad more than 1/4 inch thick)
• 1 lb waxy red potatoes, washed and very thinly sliced
• 2 tablespoons olive oil
• 1/2 cup grated gruyere cheese
• 1/2 cup crumbled feta cheese
• 1 cup grated mozzarella cheese
• sea salt and black pepper

1. Preheat oven to 400*F.
2. Melt the butter in a 9-10 inch ovenproof frying pan (cast iron is great) over medium heat. Add the thyme and onion and cook for 5 minutes. Spread out evenly in the pan.
3. Place the potato, oil, cheeses, salt and pepper in a bowl and toss to combine.
4. Top the onion with the potato mixture, spreading out evenly over the onions, and bake for 45 minutes or until golden brown and cooked through. Turn upside down to serve.
5. Note: For an extra cheesy tart, double the amount of mozzarella.

butter, thyme, onion, waxy red potatoes, olive oil, gruyere cheese, feta cheese, mozzarella cheese, salt

Taken from www.food.com/recipe/upside-down-potato-onion-tart-498766 (may not work)