My favorite way to cook eggplant is dead easy. I use "vodka marinara" sauce (from a jar, it's lighter colored than regular marinara; my favorite is Trader Giotto's from Trader Joe's but any brand would work). I don't know what it is about this sauce, but the flavor is perfect with eggplant.
Cut the eggplant into cubes. I also use sweet onion, red bell pepper, summer squash, and zucchini -- but you could use just onion and eggplant. Throw it in your biggest frying pan with the onion and a bit of olive oil, cook until the eggplant softens slightly. Add the other veggies and the marinara sauce and simmer 15-20 minutes until the eggplant is cooked through. Serve with pasta or rice and parmesan cheese. Also good with chicken or ham added for a 1-pot meal.
You could just throw everything in the pan at the start, but by the time the eggplant cooks through, the summer squash and red pepper may be a little too soft. Eggplant that's under-cooked will have a bitter or tanic flavor.
