Crispy Chicken Over Turmeric-Lemon Cabbage and Peas

1 tsp. cumin seeds, coarsely crushed
1 tsp. garlic powder
1 tsp. ground coriander
½ tsp. ground turmeric
2 tsp. kosher salt, divided, plus more
2½ lb. skin-on, bone-in chicken thighs (5–6)
2 tsp. extra-virgin olive oil (optional)
1 onion, thinly sliced
2 garlic cloves, thinly sliced
1 small head or ½ large head green cabbage (about 1½ lb.), thinly sliced
1 lemon, sliced, seeds removed
⅓ cup fresh or frozen, thawed peas
Cilantro leaves with tender stems (for serving)

Preheat oven to 350°F. Mix cumin seeds, garlic powder, coriander, turmeric, and 1 tsp. salt in a small bowl.
Arrange chicken thighs on a plate and pat dry with paper towels. Season generously with spice mixture on both sides. You won’t need all of it; set leftover spice mixture aside for adding to cabbage later.
Working in 2 batches if needed, arrange chicken thighs, skin side down, in a cold large cast-iron skillet and set over medium-low heat. Cook, undisturbed, until skin underneath is golden brown, about 10 minutes. Increase heat to medium and cook until skin is deep golden brown, about 2 minutes. Turn chicken over and cook 5 minutes. Transfer to a plate. Reduce heat to medium-low if cooking chicken in batches.
If skillet seems dry, add oil, then cook onion and garlic over medium heat, stirring occasionally, until onion is translucent, about 3 minutes. Stir in reserved spice mixture and cook, stirring often, until fragrant, about 2 minutes. Add half of cabbage and stir to combine. Let cook 1 minute to wilt slightly, then add remaining cabbage and 1 tsp. salt and stir again to combine. Taste and season with more salt if needed. Add ½ cup water and cover (a baking sheet works great if you don’t have a lid). Cook cabbage 10 minutes.
Arrange chicken, skin side up, on top of cabbage, then wedge lemon slices evenly between thighs. Transfer to oven and bake until cabbage is tender and chicken is cooked through (an instant-read thermometer inserted into the thickest part of a thigh should register 165°F), 22–25 minutes. Remove from oven.
Scatter peas over chicken. Return skillet to oven and bake 5 minutes. Remove from oven and scatter cilantro over to serve.