Preheat a grill or grill pan to medium-high.
Place a large pot of water over high heat to boil. Once boiling, add some salt, drop the pasta and cook to al dente according to package directions.
In a high-sided skillet with about an inch of water, parboil the sausages until cooked through, about 8-10 minutes. Remove them from the skillet and split them lengthwise. Drizzle with about a tablespoon of EVOO and place on the grill to crisp up both sides.
While the pasta and sausages are cooking, combine the garlic, parsley, vegetable stock, and red wine vinegar in a food processor. Pulse a few times to combine then stream in the EVOO while the machine is running.