Bring a large pot of lightly salted water to a boil. Add the beet greens, and cook uncovered until tender, about 2 minutes. Drain in a colander, then immediately immerse in ice water for several minutes until cold to stop the cooking process. Once the greens are cold, drain well, and coarsely chop.
Heat the olive oil in a large skillet over medium heat. Stir in the garlic and red pepper flakes; cook and stir until fragrant, about 1 minute. Stir in the greens until oil and garlic is evenly distributed. Season with salt and pepper. Cook just until greens are hot; serve with lemon wedges.
