Cut sweet potato horizontally in ¼-inch thick slices.
Preheat Indoor/Outdoor Grill to setting 4.
Brush each side of sweet potato slices with olive oil and sprinkle with salt and pepper.
Place on grill and allow slices to cook for 4 to 6 minutes per side. (Allow some burnt parts to sweet potato to enhance flavor.)
After sweet potatoes are cooked, remove from grill and place avocado slices and mixed spicy greens on top of slices. Serve immediately.