Preheat your grill to medium-high.
Bring a pot of water to boil on the stovetop. Blanch the wedges for 3 to 4 minutes and drain.
In a bowl, combine all the ingredients for the spicy seasoning.
1 tbsp. mixed or black peppercorns, 2 tsp. dried sage, 1 tbsp. dried oregano, 1 tbsp. dried thyme, 2 tbsp. paprika, 1 tsp. cayenne pepper, 3 tsp. garlic powder
Place the wedges in a big bowl, drip the oil onto them, and mix well, making sure all the wedges are coated with olive oil.
2 lb. sweet potatoes, 1 tbsp. olive oil
Add the spicy seasoning and mix well again, making sure everything is well covered. You might not need to use all of the seasonings.
Grill the wedges for approximately 10 minutes or until nicely charred and soft, turning them once in a while.