Preheat the oven to 425°F (220°C).
Pat the chicken thighs dry with paper towels.
Season both sides with Butcher Box BBQ spice, 1 tsp kosher salt, and black pepper.
Let sit at room temperature while preparing the vegetables.
Cut the cauliflower into bite-sized florets and slice the purple onion thinly.
In a large bowl, toss the cauliflower and sliced purple onion with olive oil, lemon pepper, and a pinch of salt.
Stir together the yogurt, garlic, lemon juice, salt, cilantro, dill, and olive oil in a small bowl. Adjust seasoning to taste.