Preheat the oven to 425ºF. Slice the cabbage into ½-inch thick steaks starting from the top all the way through the bottom (leave the core in). Lay the steaks on a baking sheet and drizzle with olive oil. Sprinkle with garlic, salt, and pepper. Bake for 20-25 minutes.

While the steaks are cooking, heat the balsamic vinegar in a saucepan over medium-high heat.  Lightly simmer until the vinegar has reduced by half. Drizzle about ¼ cup of the balsamic glaze over the steaks before serving.