Preheat the oven to 375°F.
Place the beets on top of a large sheet of aluminum foil and fold the edges over to create a pouch (the beets should be completely enclosed in foil). Lay pouch on top of a baking sheet to avoid any dripping onto the bottom of the oven and roast until tender, about 1 hour.
Once cool, slough away the beet skins with your fingers (or a paper towel) and discard.
Cut beets into wedges and transfer to a food processor.
Add the garlic, tahini, sour cream, lemon juice, salt and a few grinds of fresh pepper and process until smooth.
Taste and season with additional salt and pepper if needed.
Eat!