This is the exact process I use every time, and it's nearly impossible to mess up.

Prep the eggplant. Wash 4 medium eggplants under cold water and pat them dry. Peel the skin off completely using a vegetable peeler or paring knife. Cut each eggplant into 1-inch cubes and toss them onto a large baking sheet.

Season generously. Drizzle olive oil over the cubed eggplant. Sprinkle with salt and black pepper. Toss everything until every piece is lightly coated. Don't skip this step or you'll end up with dry, bland puree.

Roast at 400°F. Slide the baking sheet into a preheated 400°F oven and roast for 40 to 45 minutes. Halfway through, around the 15 to 20 minute mark, pull the sheet out and stir the cubes with a spatula so they brown evenly on all sides.

Let it cool slightly. Once the eggplant is soft, collapsed, and starting to turn golden brown at the edges, pull it out of the oven. Let it sit on the counter for 5 to 10 minutes. You don't need it to be completely cool, just cool enough that your blender or food processor won't overwork.

Puree until smooth. Transfer all the roasted eggplant into a food processor or high-speed blender. Blend on high until the texture is completely smooth and creamy. If it looks too thick, you can add a tablespoon of olive oil or water to loosen it up, but usually the eggplant releases enough moisture on its own.

At this point, you have a base puree that's ready to use immediately or store for later. It should look glossy, taste mildly sweet with a hint of caramelization, and have the texture of a thick hummus or a loose spread.