Start with halving the cubanelle peppers.
Start by cooking 1 cup of brown rice according to the package instructions, add 1 teaspoon of salt and olive oil when cooking the rice.
While the rice is cooking, chop the onion and celery. Sauté the onion and celery in the olive oil until they are soft and translucent.
Next, stir in minced garlic along with chili powder and 1 tsp. of cumin powder. Be careful not to burn the garlic when you are sautéing it; if it starts to become brown or singed, turn down the heat or remove the pan from the burner for a few moments before continuing to cook.
Once the onions, garlic, and spices are cooked through, add in rinsed black beans along with the tomato salsa (homemade or store-bought) and continue cooking the mixture for another few minutes over low heat. At this point, you can taste the mixture to adjust any seasonings as needed.
When the rice is done cooking and has cooled slightly, fold it into the vegetable/bean mixture until everything is fully incorporated.
Finally, preheat your oven to 375 degrees and pile the filling into halved cubanelle peppers that have been brushed lightly with olive oil on all sides.
Top each pepper with some shredded mozzarella cheese and pop them in the oven for about 20 minutes or until they are heated through and the cheese is melted on top.
Garnish with chopped fresh cilantro if desired before serving hot over a bed of arugula or mixed greens.