Heat a small skillet over medium-high heat and sauté onion and jalapeño for 5 minutes.
Reduce heat to low-medium and add black beans, garlic powder, cumin powder, two tablespoons of cilantro. salt and pepper. Mix well together. Cover and let simmer for 3 minutes, then remove from heat. Allow mixture to cool down for a few minutes.
In the meantime, in a small mixing bowl add avocado, lime juice, two tablespoons of cilantro, salt and pepper. Mash and mix it well together, then set aside.
Laying tortilla flat, spread mashed avocado and add ½ cup of cooked black beans in the middle along with tomatoes and ¼ cup of feta cheese. Invert the left and right-hand sides and roll it up. Use water on edges to seal the wrap.
Heat a flat pan on medium heat, spread some grease and place the burrito in the middle. Flip occasionally until all sides are golden brown. Remove from heat and let sit for a few minutes until it cools down.
Repeat with a second tortilla.
Cut burritos in half and serve hot.