Preheat your Blackstone OpenFlame with a solid bed of hot embers.
In a small saucepan, combine the butter, thyme, garlic, and hot sauce. Slice the lemon in half, squeeze the juice into the pan, and add the squeezed lemon halves. Season with a few shakes of Blackstone Lemon Peppercorn Seasoning. Place the pan on the grill grates over the embers and cook until the butter is melted and lightly bubbling, about 5 minutes. Move the pan to a cooler area of the grill to keep warm.
Butterfly the chicken legs by making a lengthwise cut down to the bone. Open the meat slightly to create more surface area for seasoning and even cooking.
Drizzle the chicken legs with a little olive oil and season generously with Blackstone Lemon Peppercorn Seasoning.
Place the chicken legs over the hottest part of the grill. Cook for about 5 minutes, then flip. Adjust the grill grate height as needed to control the heat.
Using a basting brush, brush the chicken generously with the lemon-garlic butter. Continue cooking, flipping and basting every 2–3 minutes, until the chicken is golden brown, slightly charred, and fully cooked through.
Transfer the chicken to a serving platter and garnish with fresh parsley and an extra squeeze of lemon juice before serving.