1. Bring a medium pot of water to a boil. Add radishes to pan; cook 4 minutes or until crisp-tender. Drain.
2. Melt butter in a medium skillet over medium-high heat. Add radishes to pan; sauté 3 minutes or until butter is browned and fragrant. Add rind, juice, and salt; cook 1 minute, stirring occasionally. Remove pan from heat; stir in radish leaves and pepper.