Slice cabbage into 1/2-inch-thick pieces vertically. (See video.)
Melt 1 tablespoon butter or heat 1 tablespoon avocado oil in a cast-iron skillet over medium-high heat. Add 1 or 2 cabbage steaks (depending on the size of your cast-iron skillet); lightly season with a dash of salt, black ground pepper, and a pinch of garlic powder. Cook 3 to 4 minutes. Place the cabbage steaks in a single layer, seared side up on a baking sheet lined with parchment paper. Repeat this process with remaining cabbage, adding more butter or oil to the skillet as needed. Bake for 15-20 minutes.
While the cabbage steaks are baking, whisk all the dressing ingredients in a small bowl. Mix well and set aside.
Once the cabbage steaks are done, dish and drizzle with the dressing, and serve with lime wedges and cilantro. YUM!