Prepare the chile lime tahini sauce. In a medium bowl, whisk together the tahini, adobo sauce, lime juice, and salt. Then, add the ¼ cup ice water. Slowly whisk to combine and then speed up your whisking. The sauce should become slightly pale and be fluid enough to drip off of your whisk. Add more ice water by the tablespoon if necessary. Check the sauce for seasoning, adjust, and then set aside.
Slice the sweet potatoes crosswise into ½ inch thick slices. Place the sweet potato slices in a large pot and cover with water. Put a lid on the pot and bring the sweet potatoes to a boil. Let the sweet potatoes boil until they yield to the prick of a paring knife with minimal pressure, about 4 minutes.
Drain the sweet potatoes and allow them to dry off a bit. Preheat your grill to high.
Lay the par-boiled sweet potato slices out on a baking sheet in a single layer. Spray the sweet potatoes with your oil spray and season them with salt and pepper. Flip the slices over and repeat with the other side.
Grill the sweet potatoes until char marks appear, about 4 minutes per side. Transfer the grilled sweet potatoes to a serving platter. Drizzle the chile lime tahini sauce over top and garnish with fresh herbs, sliced chiles, toasted nuts/seeds etc! Enjoy immediately.