Peel the daikon radish and slice into ¼" slices. Bring a pot of water to a boil and add slices. Cook 7-9 minutes or just until tender-crisp. Drain well, season with salt & pepper.
Heat cream cheese and butter in a skillet until melted and creamy. Add garlic, broth and cream. Simmer until slightly thickened, about 5 minutes.
Place half of the daikon slices in the baking dish. Top with ½ of the onions and ½ of the cream sauce.
Add remaining daikon and remaining cream sauce.
Cover with foil and cook 40 minutes. Remove foil, top with cheese if using and cook an additional 15-20 minutes or until tender and cheese is browned.
Notes
*You can prep this recipe a day in advance and refrigerate. *Since daikon does not freeze well, make only what you plan to eat and store it in the refrigerator. Consume any leftovers within 2-3 days.