Salt-roasting is a genius method for cooking not just beets but all root vegetables, generating tons of flavor with no fuss. Salt does the work here, encasing the beets, then baking right in. The result? Beets that are tender and seasoned from the outside in. Worth it to make a farmer's market run.
Preheat oven to 425 degrees F. Remove greens from beets (reserve if making Amanda Cohen's Beet-Green Pesto). Scrub the beets clean. Place them in a deep roasting pan, then bury them completely in salt and pack it down. Bake 1 hour.
Remove beets from oven. Insert a paring knife through the salt crust and into a beet to check for doneness. (On the off chance they're not done, return them to the oven and check every 10 minutes.) Crack the crust with a spoon, then remove the beets to a bowl, scraping the salt off them. Careful, they'll be very hot! (You can save the salt for future beet-roasting—just get rid of the clumps and store in an air-tight container in the fridge or freezer.) Rinse beets in water to remove any lingering clumps of salt. Allow to cool so they can be peeled.
Peel beets with a paring knife, starting with the light-colored ones first, so you don't stain them with juice from the darker beets. First cut the root end, then peel the skin. The skin should peel off easily—a sign they're cooked properly. Cut into quarters, or, if they're smaller, leave whole.