Pre-heat your grill to medium high.

Wash, dry and cut the sweet potatoes to ½" round slices and place them in a large bowl. Toss the sweet potato slices with olive oil, kosher salt, black pepper, and chopped rosemary.

Place the sweet potatoes directly on the grill grates and cook undisturbed for 5-7 minutes. Turn them over and cook another 5-7 minutes or until the potato slices are just tender when poked with a knife or toothpick. Transfer them to a serving platter, drizzle the rosemary hot honey over the sweet potato slices and serve.

Melt the butter in a small saucepan, then add the honey, red pepper flakes and rosemary.  Stir over medium heat just until the honey has completely melted. Don't let the mixture boil.

Remove it from the heat, stir in the lemon juice and let the honey butter sauce sit for about 10 minutes. At this point you can strain it to remove the red pepper flakes or use it as is.