Heat the 2 tablespoons coconut oil over medium-high heat in a large frying pan or pot big enough to hold all the cabbage. Once it melts, add the 1 small head green cabbage, cored and chopped; 2 medium carrots, thinly sliced; 1 medium white onion, thinly sliced; 1 medium green bell pepper, thinly sliced; 6 cloves garlic, thinly sliced; 1 tablespoon kosher salt; and 1/2 teaspoon freshly ground black pepper. Toss to coat in the oil and stir-fry until everything starts to wilt, brown in spots, and release its liquid, about 15 minutes.