Step 1

Set a steamer basket in a large pot or pan and fill with water to just below the basket. Bring water to a steady boil.

Step 2

Add the celery root and cauliflower florets (you may need to do this in two batches depending on the size of your pot); reduce to a low simmer. Cover and steam until tender (about 15 minutes).

Step 3

Transfer vegetables to the bowl of a food processor, add butter and salt and process until smooth (you may need to add 1 or 2 Tablespoons of the steaming liquid to loosen the puree to the right consistency). Season with additional salt and pepper to taste and keep covered while making the garlicky greens.

Step 4

You can also refrigerate the puree up to 1 day ahead of time and reheat in a heatproof glass bowl set over a pan of simmering water before topping with the sautéed chard.

Step 5

Stack chard leaves, roll together and slice them into 1/4-inch strips. Cut the stems three quarters of the way down very thinly.

Step 6

Heat the butter (or olive oil) in a large skillet or sauté pan with a lid. Add the garlic and red pepper flakes and sauté for 30 seconds just until the garlic is fragrant.

Step 7

Stir in the still wet chard leaves and stems, turning it in the butter and garlic for 2 to 3 minutes until just starting to wilt.

Step 8

Cover the pan and let cook for another 2 to 3 minutes until both the sliced stems and leaves are just tender. Season with a pinch or two of sea salt .