Melt the butter in a large pot over medium heat. Stir in the diced onion and sea salt to taste; cook and stir until the onion has caramelized to a deep brown, about 15 minutes. Once caramelized, pour in 6 cups of chicken stock and the quinoa; bring to a boil over high heat. Reduce heat to medium-low, cover, and simmer until the quinoa is tender, 20 to 25 minutes.
Meanwhile, heat the olive oil in a large skillet over medium-high heat. Brown the sausages on all sides in the hot oil, then remove and cut into 1/2 inch thick slices. Return the sausage to the skillet, and continue cooking until browned on all sides and no longer pink in the center. Remove to drain on a paper towel lined plate, and keep warm.
Reduce the heat to medium, and stir the sliced onion into the remaining oil in the skillet. Cook until the edges of the onions begin to turn a golden color, 3 to 5 minutes. Add the garlic, and cook 1 minute more. Season with the paprika and cumin, then stir in the red bell peppers, yellow bell peppers, poblano chile peppers, and 1 cup of chicken stock. Bring to a simmer, then cook until the peppers soften, and the mixture reduces and thickens, 10 to 15 minutes. Return the sausage to the skillet, season to taste with salt and pepper, and continue cooking until the sausage is hot. Serve over a bed of quinoa.