Heat the avocado oil in a skillet over medium-high heat. Add sausage and sauté for 2 minutes without stirring. Continue cooking for another 3 minutes while stirring occasionally. Remove sausage from the pan and place on a plate or in a medium bowl lined with a paper towel. Continue with the next step.
Turn the heat on the skillet down to medium and add the onion. Saute for 3-4 minutes, then add the cabbage. Mix well and saute for 5-7 minutes allowing the cabbage to cook down. Add the garlic and let cook for 1-2 minutes, or until fragrant. Now add the sugar, salt, and pepper. Stir occasionally until the vegetables are at the desired doneness, another 3-10 minutes.
Add the vinegar, mustard, and cooked kielbasa. Cook for 2-3 minutes until heated through.
Serve while it’s still hot.
You could also serve it over egg noodles, rice, or even mashed potatoes.
Recipe adapted from BellyFull.