Peel and cube potatoes and boil in heavily salted water for 10 minutes. Drain and set aside.
Cut chicken into 1 inch pieces. Set aside.
Dice onion and place in a bowl with cottage cheese, sour cream, parmesan cheese, parsley, cayenne, salt and pepper. Stir to mix and add chicken and potatoes. Stir to mix and pour into prepared pan. Top with cheddar cheese.
Bake for 40 minutes or until top is golden brown and bubbling.