Cook the quinoa or brown rice according to package instructions if not already prepared. Set aside.

Heat olive oil in a small pan over medium heat. Crack the egg into the pan and cook sunny-side up or to your preferred doneness. Season with salt and pepper.

In a bowl, layer the cooked quinoa or brown rice as the base.

Arrange the black beans, cherry tomatoes, and sliced avocado on top of the grains.

Place the cooked egg on top of the bowl.

Drizzle with lime juice, sprinkle with chopped cilantro, and add crumbled feta cheese if desired. Serve immediately.