3 Yukon potatoes, sliced into 1/4-inch slices
Salt and freshly ground pepper
1/4 cup olive oil, plus extra for greasing dish and brushing on lemons
3/4 pound white fish fillets, such as cod, flounder or tilapia
4 cloves garlic, minced
2 teaspoons minced fresh thyme
1/2 lemon, juiced
1 yellow onion, sliced
3 Roma tomatoes, thickly sliced
1/2 cup good quality black olives, pitted and lightly crushed and sliced in half
1 lemon, quartered
Special Equipment: 15 1/2-by-7 1/2-inch terracotta cazuela (baking dish)