Heat the olive oil in a large skillet over medium heat.
Add the diced onion and sauté for about 5 minutes until it becomes translucent.
Stir in the minced garlic and cook for an additional 1-2 minutes, being careful not to burn it.
Add the sliced kielbasa to the skillet and cook for about 5-7 minutes until it begins to brown, stirring occasionally.
Increase the heat to medium-high, and add the chopped cabbage. Stir well to combine.
Season with smoked paprika, black pepper, and salt. Cook for about 10-12 minutes, stirring occasionally, until the cabbage is tender and slightly caramelized.
Drizzle with apple cider vinegar and give a final stir, cooking for another minute.
Remove from heat, garnish with fresh parsley if desired, and serve hot.