Add the quinoa and broth to a medium sauce pot and bring to a boil. Then reduce heat and simmer until water is absorbed, approx 15 minutes. Stir often towards the end of cooking time to prevent sticking. Remove from heat and add the black beans, corn, salsa and all the seasoning. Taste and adjust seasoning as desired.
Meanwhile, preheat your oven to 400 degrees F and line a 9"x13" baking dish with parchment paper. Arrange the halved peppers, cut side up in the dish and sprinkle them with salt and pepper.
Divide the mixture among your eight pepper halves, then cover the dish with foil and bake in your preheated oven for 40 minutes. Then remove the foil and bake an additional 10 minutes.
While the peppers are baking, prepare the walnut cheese sauce, by following these directions. Then serve your peppers drizzled with the cheese sauce, and a sprinkle of cilantro, if desired.
You may use salted water to cook the quinoa instead of broth, but it won't have as much flavour. If you don't care for quinoa, you may sub for rice instead, by following the same cooking instructions, or you may use a rice cooker.To make this nut free, skip the walnut cheese sauce, and top with guacamole or salsa instead.The nutritional information is for two stuffed pepper halves, and does not include additional toppings.