Preheat oven to 350 degrees. Slice one head of cauliflower from top to base into 3/4-inch slabs. Rub both sides of each slab with fresh garlic. Sauté over medium-high heat in 1 tbsp olive oil until golden brown, about 2-3 minutes per side. Repeat for all steaks.
Lay steaks on a baking sheet (for easy cleanup, line sheet with parchment), sprinkle with salt and pepper, and roast for 20 minutes.
Puree 1/4 cup pitted kalamata olives, 1/4 cup cilantro, 1/4 cup olive oil, 1 tsp chili flakes, and 2 tsp fresh-squeezed orange juice. Drizzle dressing on steaks and serve.