Preheat a grill to 400 degrees F or a large grill pan over medium heat. Clean and oil the grill grates or grill pan.
Place the thighs on a rimmed baking sheet and drizzle with 1 to 2 tablespoons of oil until fully coated; liberally season both sides with salt and pepper. Grill the chicken skin-side down, covered, until golden brown and crispy, about 15 minutes (or up to 20 minutes, if using a grill pan). Check on the thighs occasionally to make sure they aren't burning. Flip the chicken and grill, covered, until crispy and cooked through, about 15 minutes longer.
Meanwhile, make the sauce: Combine the lime zest and juice with the peanut butter, chile paste, honey, tamari and 1/2 teaspoon salt in a small bowl. Whisk together and taste for seasoning. Transfer to a small serving bowl.
When the chicken is ready, remove it to a platter or a large shallow bowl. Drizzle with some of the sauce then sprinkle with the scallions, cilantro and peanuts. Serve immediately with the remaining sauce on the side.