Preheat the oven to 400°F. Put the eggplant in a colander and sprinkle with the salt. Let stand until moisture begins to bead on the surface of the eggplant, about 15 minutes.

Pat the eggplant dry. Spread on a sided baking sheet and pour 1⁄4 C. of the olive oil over the eggplant. Toss to coat evenly. Sprinkle with the 1 tsp. salt. Bake, turning once or twice, until tender, 25-30 minutes.

In a large skillet, heat the remaining 1⁄4 C. olive oil over medium-high heat. Add the onion and sauté until browned, 5-7 minutes. Add the zucchini, bell pepper, and garlic. Reduce the heat to medium and sauté until the pepper is tender, about 10 minutes. Stir in the tomatoes and tomato paste. Cook, stirring often, until the tomatoes have melted, about 20 minutes. Add the eggplant and cook until the flavors meld, about 10 minutes. Stir in the basil, sage, and oregano. Season with pepper and adjust the seasonings to taste. Divide among 6 small plates and serve.