Preheat your oven to 190°C (375°F). Slice the tops off the peppers and carefully remove the seeds and membranes, leaving the peppers intact. Lightly brush the peppers with a teaspoon of olive oil and place them upright in a baking dish.
Cook the quinoa in a saucepan with 2 cups of water; bring to a boil, then reduce heat and simmer for about 15 minutes until fluffy and tender. Fluff with a fork and set aside.
While the quinoa cooks, heat 1 tablespoon of olive oil in a skillet over medium heat. Sauté the chopped onion and minced garlic until fragrant and translucent, about 3 minutes. You should smell a warm aroma and see the onions turn slightly golden.
Add the cooked quinoa, black beans, corn, chopped herbs, cumin, salt, and pepper to the skillet. Mix everything thoroughly, allowing the flavors to combine and the mixture to heat through for about 5 minutes. The filling should look moist, flavorful, and well combined.
Using a spoon, carefully stuff each pepper with the quinoa mixture, pressing down gently to pack the filling. Once filled, sprinkle nutritional yeast or vegan cheese on top for a cheesy crust.
Place the filled peppers back into the baking dish and bake uncovered for 25 to 30 minutes. You'll see the peppers soften and the tops turn golden and slightly crispy. The filling should be bubbling, and the aromas will be inviting.
Remove the peppers from the oven and let them rest for about 5 minutes. This allows the filling to settle and the peppers to cool just enough to handle.
Serve the stuffed peppers warm, garnished with extra chopped herbs or a squeeze of lemon if desired. Enjoy the soft peppers with a savory, crispy filling—like a comforting hug in every bite.