Preheat the oven to 325°F.
Separate the radishes from their greens. Clean and chop the radishes. Clean and chop the radish greens.
Sauté the dieced onion and the chopped radishes in olive oil with about ½ tsp of salt on medium high heat. Use enough oil to make everything glisten, but not have a pool of olive oil underneath. 1-2 tablespoons should work. Sauté, stirring frequently, until softened. Expect about 5 minutes.
Add the garlic to the pan, and sauté for another minute or two.
Add the chopped radish greens to the skillet. Initially, they may come close to overflowing the pan, but they will quickly wilt, reducing their volume. When all of the greens are fully wilted, you are ready to add the eggs.
While the vegetables sauté, beat the eggs with the cream, ½ tsp of salt and a few cranks of the pepper grinder.
Evenly distribute the vegetables in the pan and pour the egg mixture over. Give a quick stir to suspend some of the vegetables off the bottom of the pan. Sprinkle the cheese evenly over the top.
Transfer the pan to the pre-heated oven and cook until done. Timing will vary for various reasons. Other than the true oven temperature, the biggest variable is the amount of seasonal vegetables that are in the pan. As they have just completed cooking, they hold a lot of heat. The more of them, the quicker the cook. Start checking for doneness after about 10 minutes. There should be no jiggle if you shake the pan. A toothpick test can reveal if there is any runny egg. You are going for a custardy egg. Too little time is runny and too much time is rubbery.