Steam cauliflower florets in vegetable broth until fork-tender, approximately 10 minutes.
In a small skillet, heat olive oil over medium heat and sauté minced garlic until fragrant.
Transfer the cooked cauliflower and 1/2 cup of the cooking liquid to a high-speed blender.
Add the sautéed garlic, Greek yogurt, Parmesan cheese, salt, and pepper to the blender.
Blend on high speed until the mixture reaches a completely smooth, velvety consistency.
Adjust thickness with additional cooking liquid if desired and serve immediately.