1. Preheat oven to 450°.
2. Remove stems and roots from beets; wrap beets in foil. Bake at 450° for 45 minutes or until tender. Cool beets slightly; peel and cut into 1-inch wedges.
3. Combine sour cream, onions, salt, and jalapeño in a small bowl. Divide lettuce leaves among 8 plates; top evenly with beets and jalapeño mixture.