How to Make It
Preheat the oven to 350°. Put the eggplant in a colander and toss with 1 teaspoon of kosher salt. Place a small plate on top of the eggplant and weight it down with canned goods. Set the colander in the sink until the eggplant releases its liquid, about 30 minutes. Gently squeeze the eggplant to remove additional moisture.
In a large ovenproof skillet, preferably nonstick, heat 2 tablespoons of the olive oil. Add half the eggplant and cook over moderately high heat, stirring occasionally, until browned, about 4 minutes. Transfer the eggplant to a large plate and repeat with the remaining olive oil and eggplant. Reduce the heat to low, add the onion and cook until tender, about 6 minutes. Return the eggplant to the skillet.
Meanwhile, in a large bowl, whisk the eggs with a pinch each of salt and pepper. Add the eggs to the eggplant and onion in the skillet and increase the heat to moderate. Use a spatula to pull the cooked egg into the center, allowing the uncooked egg to fill the bottom of the skillet. When the frittata is mostly set, gently stir in the dill. Put the skillet in the oven and cook the frittata until it is just set, about 5 minutes.
Shake the skillet to loosen the frittata and run a spatula around it if necessary. Carefully slide the frittata onto a platter, then let cool slightly. Cut into 12 wedges and serve warm or at room temperature.