Place a large pot of salted water over high heat and bring to a boil. Cook the pasta according to package instructions. Drain and set aside, reserving 1 cup of the pasta water for later use.
Meanwhile, cut the cabbage and onion in quarters. Sliced into strips. Remove the thickest white sections of the cabbage and keep the thinner white and green layers. Place a large skillet over medium heat. Add the bacon and saute until crisp. Then add the cabbage and onions. Saute for 5 minutes, then salt and pepper to taste. Toss in the garlic and saute another 5 minutes.
Once the cabbage is tender, toss the pasta in the skillet. Stir to mix and add a little of the reserved pasta water to help blend the flavors. Taste for salt and pepper, then garnish with fresh chopped parsley. Serve warm.