Low-Carb Cabbage Enchiladas

1 head green cabbage

1 tbsp. extra-virgin olive oil

1 large onion, chopped

1 red bell pepper, chopped

Kosher salt

2 cloves garlic, minced

2 tsp. ground cumin

2 tsp. chili powder

3 c. cooked and shredded chicken

1 1/3 c. red enchilada sauce, divided

2 tbsp. chopped cilantro, plus more for garnish

1 c. shredded Monterey jack

1/2 c. shredded cheddar

Sour cream, for drizzling