1/4 c. olive oil, divided
3 cloves garlic, sliced thin
1 tsp. dried oregano
1 24-oz. can Italian whole tomatoes
12 fresh sage leaves
1/2 lb. grated mozzarella cheese
1/2 c. grated Parmesan cheese
Meanwhile, set a a large saucepan over medium heat. Add olive oil, then garlic, and saute until softened, about 2 minutes. Add dried oregano and saute until fragrant, about 1 minute. Using your hands, crush tomatoes one at a time into the garlic. When all of the tomatoes are crushed, add the remaining tomato sauce from the can as well. Add 1 tsp. of salt, a few grinds of black pepper, then turn the heat down and simmer the sauce over low heat for 10 minutes, stirring a few times. Remove from heat and set aside.
In a small skillet, heat the remaining 2 Tbsp. of olive oil over medium heat. When the oil is hot, add the sage leaves in an even layer. Fry for about 30 seconds per side, turning with tongs, until lightly crisp. Drain on a paper towel, reserving oil.
Lay another two layers of paper towels over the eggplant and press firmly to absorb the eggplant liquid. Using the fried-sage oil, brush both sides of each eggplant slice with the oil, laying slices on a plate as you. Grill the olive oil slices for 3-4 minutes per side, or until lightly browned and tender.
Preheat oven to 375 degrees F.
To assemble the dish, spoon about 1 c. of tomato sauce into the bottom of a 10-inch tart pan (enough to cover the bottom). Lay one layer eggplant slices in the sauce. Top slices with a bit more sauce, then sprinkle half of the cheeses over the eggplant. Distribute the sage leaves over the cheese. Repeat with the remaining eggplant, more sauce, and the remaining cheese. Bake for 30 minutes, or until cheese is bubbly and browning a bit in spots. Let rest for 10 minutes. Serve hot.