Cut the cabbage in half from top to bottom, slicing through the core of the cabbage. Use a paring knife, make a triangle shape as you cut out the core so it will easily pop out. Discard the core.
Place cabbage cut side down on a cutting board, then use a sharp chef's knife to thinly slice into strips. Set aside.
In a large glass jar or storage container, combine red wine vinegar, kosher salt, sugar, garlic, and peppercorns. Fill with sliced cabbage, then top with water. Securely seal with a lid, then shake.
Let sit at room temperature or in a refrigerator for at least 1 hour. Serve on tacos, salads, sandwiches, or any way you like!
It's sweet, adds a gentle acidity, and will liven up any dish you serve it with!