Chicken Chorizo Casserole (Paleo, gluten-free)

medium sweet potatoes, peeled and cut into 1-2" cubes

small onion, diced

broccoli florets (I use frozen to keep this recipe easy!)

to 2 lbs boneless skinless chicken breast, cut into 1-2" pieces

fresh (not smoked) chorizo sausage, removed from casing and crumbled

TB melted lard or fat of choice for greasing dish

unrefined salt and pepper