Preheat oven to 400°. Cut each beet into 6 wedges; place in a shallow dish. Add olive oil and salt; toss gently to coat.
Cut a piece of heavy-duty foil about 12 in. long; place in a 15x10x1-in. baking pan. Arrange beets on foil; top with rosemary. Fold foil around beets and seal tightly.
Bake until tender, about 1 hour. Open foil carefully to allow steam to escape. Discard rosemary sprigs.
Notes
Roasted Beets Tips
How do you store roasted beets?
Store leftover roasted beets in an airtight container for 3 to 4 days. When you're ready to eat again, you can serve roasted beets cold or warm.
What can you serve with roasted beets?
Roasted beets go well with dishes such as mashed potatoes, Brussels sprouts, and turkey.