Preheat the grill or grill pan to medium-high heat.
Cook the sausage on the outdoor grill or grill pan for about 12 minutes, turning a quarter turn every 3 minutes.
While the sausage is cooking, heat the canola oil in a large skillet over medium-high heat. Add the cabbage, onion, garlic, red pepper flakes, salt, and pepper. Cook, stirring often, until the cabbage has wilted slightly, about 4 minutes.
Stir in the beer, vinegar, mustard and the brown sugar and simmer for 5 minutes. Add the apples, cover partially with a lid, to allow some steam to escape. Cook the cabbage and apples over medium-low heat until they are tender, about 8 minutes.
Reserve 2 sausages and 1 cup of the apple sauerkraut for online Round 2 Recipe.
Transfer the sausages and sauerkraut to a serving platter and serve.