Curried Chicken and Broccoli Casserole

cooking spray (such as Pam®)

bunch broccoli, cut into chunks - or more to taste

cooked rotisserie chicken, meat removed from bones and chopped

cream of chicken soup

mayonnaise

lemon juice

curry powder

salt and ground black pepper

shredded Cheddar cheese

crushed corn flakes cereal

slivered almonds (optional)