Sheet Pan Chicken and Cauliflower Bake

Name: Sheet Pan Chicken and Cauliflower Bake
Ingredients: Neutral oil, for greasing; 1 large head cauliflower (about 2.5 lbs pre trimming), cut into florets, large florets halved or quartered if necessary (see photo above as a reference); 1 large onion, sliced; 5 tablespoons olive oil, divided; Kosher salt and fresh pepper, to taste; 1 tablespoon whole cumin seeds or ground cumin, see notes above; 1 tablespoon whole coriander seeds or ground coriander, see notes; 2 teaspoons smoked paprika; 1/2 teaspoon cayenne; 2 cloves garlic, minced; 6 boneless, skinless chicken thighs, about 1.5 lbs.; Lemon wedges, flatbread, and yogurt sauce (see notes) for serving