Preheat your oven to 400F.
Heat an oven-safe skillet over medium heat and drizzle with oil. Add the chopped onion & broccoli. Cover and cook, stirring occasionally, for 3-4 mins to let the veggies soften. If the veggies appear too dry, add a splash of water or chicken broth.
Toss in the chopped spinach, salt, pepper, chili powder, and pre-cooked chicken.
Transfer chicken and veggie mixture to a casserole dish.
In a bowl, whisk together the Greek yogurt and enchilada sauce, then pour over casserole dish. Top with 1 to 2 cups cheese. I went lighter, but you can always add however much you want.
Pop in the oven for 10–15 mins and cheese is nice and bubbly.
Let rest for 5 mins, top with cilantro, avocado, sour cream or yogurt, and jalapeño.
