Split cauliflower evenly by cutting through core from bottom to top. Trim uncut side of each “steak” so that both sides are flat and each piece is about 1” thick.
Reserve 1 teaspoon seasoning blend and set aside. Place the remainder in a small bowl. Combine with melted butter and 3 tablespoons olive oil. Spread mixture over cauliflower steaks and place on grill, making sure to flip often. Remove cauliflower from heat once tender, about 10–12 minutes.
Whisk together reserved teaspoon of seasoning blend with Greek yogurt, lemon juice, and 2 tablespoons olive oil.
Warm chickpeas in a small pan, adding salt and pepper to taste.
To plate, layer seasoned yogurt with a spoonful of warmed chickpeas. Place the cauliflower on top of the chickpeas and garnish with herbs. Finish with a drizzle of olive oil and serve!