In a large pot over medium heat, heat the tablespoon of olive oil. Stir in the onion and sea salt to taste; cook and stir until the onion has caramelised to a deep brown, about 15 minutes. Once caramelised, pour in 1.5 litres of chicken stock and the quinoa; bring to the boil over high heat. Reduce heat to medium-low, cover, and simmer until the quinoa is tender, 20 to 25 minutes.
Meanwhile, heat the remaining olive oil in a large frying pan over medium-high heat. Brown the sausages on all sides in the hot oil, then remove and cut into 1cm thick slices. Return the sausage to the pan, and continue cooking until browned on all sides and no longer pink in the centre. Remove to drain on a kitchen paper lined plate, and keep warm.
Reduce the heat to medium, and stir the sliced onion into the remaining oil in the pan. Cook until the edges of the onions begin to turn a golden colour, 3 to 5 minutes. Add the garlic, and cook 1 minute more. Season with the paprika and cumin, then stir in the red peppers, yellow peppers, chillies and 250ml 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 pan, season to taste with salt and pepper, and continue cooking until the sausage is hot. Serve over a bed of quinoa.