This can be made a day ahead and reheated in oven or on stovetop. You can do this with simply frozen cauliflower or if you are not watching carbs, try other root veggies: add a few carrots, celeriac, or sweet potato to the pot. Makes a great topping for Shepherd's Pie.
Place fennel and parsnips in large pot and add water until barely covered. Simmer until they start to soften. Add cauliflower, stir and cook for 5-10 minutes longer until cauliflower is soft to the fork but not mushy. Drain and place in food processor. Pulse until almost smooth.Open the coconut milk can (do NOT shake beforehand). Spoon the thick cream from the can into small saucepan. Discard coconut water or save for another use. Add garlic and simmer for a few minutes until coconut milk starts to take on garlic flavor. Add salt and pepper to taste. Add garlic/coconut cream mixture to food processor and pulse until desired consistency.