Heat a grill pan over medium-high heat, or preheat grill to 400°.
In a large bowl, stir together radishes, melted butter, thyme, salt, and pepper until coated. Working in batches, place radishes in an even layer in pan or on grill. Grill, turning once, until tender, 3 to 4 minutes per side. Garnish with thyme, if desired.
Recipe by Southern Lady Magazine at https://southernladymagazine.com/grilled-radishes-recipe/