If using a jar/can of pearl onions, drain and rinse. If using fresh pearl onions, soak in a bowl of warm water for 5 minutes to loosen the skin. Using a pairing knife, cut off the ends and remove the outer skin. Place onto a large baking sheet and set aside.
Using a vegetable peeler, peel the beets and place on a non-wood cutting board (a wood cutting board will stain). Slice the beets into quarters or evenly sized pieces and add to the baking sheet. Toss with 2 tablespoons of olive oil and season with salt and pepper. Place in the middle of the oven and cook for 25-30 minutes, stirring once or twice midway through.
Whisk together the balsamic vinegar, maple syrup, herbs and 1 tablespoon of olive oil. Set aside.
While the beets are cooking, heat the olive oil in a pot on medium-high heat and saute the garlic for one minute. Add the chopped celery root, coconut milk, water, salt and pepper. Bring the liquid to a boil, then reduce the heat to low, cover the pot and simmer for 15 minutes.
Turn the stove off and use a stick blender to puree the celery root mixture until smooth. Cover the pot to keep warm until ready to serve. (*Alternatively, pour the ingredients into a high-powered blender to puree).
Once the beets and onions have cooked, drizzle the balsamic mixture on the baking sheet, toss to combine and cook for an additional 5 minutes.
Serve by scooping a portion of the celery root puree into a bowl and topping with roasted beets, pearl onions and a handful of microgreens.