To cook the beets:
- Preheat oven to 375F
- Wash beets under cool running water and pat dry
- Lightly coat beets in olive oil and a pinch of kosher salt
- Place beets in a baking dish with just enough water to cover the bottom of the dish
- Cover with a lid or foil and cook for about 45-60 minutes, until there is no resistance when pierced by a fork
- Remove from oven and let cool down enough to handle, then carefully rub the skins off
- Cut the beets into the desired bite-size shape and submerge with the cold brine
- Beets will hold indefinitely in the brine under refrigeration