Heat oven to 400ºF. Place a piece of parchment paper over baking sheet.
Bring a large pot of water to boil for pasta.
Place chicken and spinach in bowl. Grate 1 clove of garlic into bowl or finely chop and add garlic. Grate 3-4 tablespoons of onion directly into bowl. Combine 1/2 cup of cheese and breadcrumbs with nutmeg and barely moisten with milk, no more than 1/4 cup. Sprinkle the bread-cheese mixture into chicken then add egg, parsley, salt and pepper and 2 tablespoons tomato paste.