Get started by warming a large skillet over medium heat. Add half of the bacon grease (or your chosen oil) to the pan.
Sauté the sliced sausage for just a few minutes until it gets a nice, light brown color. Take it out of the skillet and set it aside, letting any delicious drippings stay in the pan.
Into the same skillet, add the remaining bacon grease (or oil), diced onion, salt, and pepper. Cook, stirring occasionally, for several minutes until the onions become tender and just begin to turn golden – this brings out a natural sweetness!
Push the onions to the sides to create a small clear spot in the center of the skillet. Add the minced garlic there and sauté for about 20 seconds until it smells fragrant, but be careful not to let it burn, as this can make it bitter.
Stir in the butter and smoked paprika, letting the paprika toast gently for about a minute to deepen its flavor. Then, pour in the apple cider vinegar.
Add the shredded cabbage to the skillet. Give everything a good toss to combine and cook for 10-12 minutes, stirring every so often, until the cabbage is perfectly tender-crisp.
Return the cooked sausage to the skillet along with the optional red pepper flakes. Continue to cook for a few more minutes, ensuring the sausage is heated all the way through. Serve immediately and savor this simple, satisfying dish!