For the casserole
01 -
12 oz (340 g) dried spaghetti
02 -
3 cups (420 g) cooked chicken, chopped or shredded
03 -
2 cans (10.5 oz each/298 g each) cream of chicken soup
04 -
2 cups (480 g) sour cream
05 -
10 oz (280 g) frozen chopped spinach, thawed and squeezed dry
06 -
2 cloves garlic, minced
07 -
1 teaspoon onion powder
08 -
1/2 teaspoon black pepper
09 -
1/2 teaspoon kosher salt, plus more for pasta water
10 -
1 1/2 cups (170 g) shredded Monterey Jack cheese, divided
11 -
3 oz (85 g) French fried onions, divided
For the pan
12 -
Nonstick cooking spray or 1 teaspoon butter