In a dutch oven, heat a drizzle of EVOO over medium-high heat. Add the knockwurst pieces in 2 batches and cook, turning once, until browned and crisped. Reserve the knocks on a plate. Add a drizzle more EVOO to the pan, then add all but 1/4 cup onion, the celery, carrot and bay leaf; season with salt, pepper and the paprika. Cook until the vegetables are tender, about 10 minutes. Add the beer and cook until reduced by half. Add the baked beans and chicken stock, bring to a bubble and slide the knockwurst back into the stoup to heat through. Serve in shallow bowls and top with a swirl of mustard, the reserved 1/4 cup onion and the pickle. Serve with the bread and butter.