Wash and dry all produce. Preheat oven to 425 degrees. Halve eggplant lengthwise, then cut into 1-inch-thick wedges. Halve, peel, and cut onion into 1/2-inch wedges. Toss eggplant and onion on a baking sheet with a drizzle of olive oil. Season with salt and pepper. Roast in oven until browned, about 25 minutes.

Meanwhile, put 11/2 cups water and a pinch of salt in a small pot and bring to a boil. Once water is boiling, add quinoa. Reduce to a simmer and cover. Cook until quinoa is tender and water is absorbed, about 15 minutes. Stir in peas and remove from heat. Keep covered until rest of meal is ready.

Pick mint leaves from stems. (TIP: Stems can be added to the quinoa for flavor. Discard before serving.) Finely chop mint leaves until you have 1 TBSP. Finely chop cilantro and its stems. Zest lemon, then squeeze juice into a small bowl.

In another small bowl, whisk chopped mint, cilantro, half the lemon juice, a pinch of lemon zest, and 2 TBSP olive oil. Season with salt, pepper, and a pinch of chili flakes (to taste).

Add sour cream and 2 TBSP water to the bowl with the remaining lemon juice and combine. Season with salt, pepper, and a pinch of remaining chili flakes (to taste).

Fluff quinoa with a fork, then divide between plates. Top with eggplant and onion. Sprinkle with feta cheese, then spoon crema and dressing on top.