(Note: this recipe would normally use 16 frozen Pepperidge Farms pastry sheets which DO CONTAIN GLUTEN, so you need to find a gluten-free alternative for this, or simply skip this step in the recipe).
8 skinless, boneless chicken breasts
1 teaspoon salt
½ teaspoon pepper
4 cups chopped fresh spinach (or 1 package frozen spinach, drained)
1 medium onion, chopped
2 tablespoons olive oil
4 ounces cream cheese (same as ½ block)
½ cup crumbled feta cheese
½ cup shredded cheddar cheese
1 egg yolk, slightly beaten
1 tablespoon gluten-free flour or gluten-free baking mix
Beat the chicken breasts into thin cutlets and flatten. If chicken breasts are somewhat thick, use a good knife and cut the chicken breast in half, forming a pocket. Be careful not to cut the chicken breast in half. You will end up being able to open the chicken breast like opening a book... so youll end up with a very large, but thin chicken breast. Do this for each chicken breast & set aside.
Sauté spinach & onion in oil until onions are tender & translucent. Remove from heat. Toss in all cheeses, egg, and gluten-free flour into pan and stir well.
Put about an ice cream scoop size dollop of spinach/chicken/gluten-free flour mixture on each chicken breast and spread somewhat thin. Then roll each chicken breast into a roll that resembles a pastry roll.
If you have a gluten-free pastry alternative, you will then wrap each chicken roll up in the gluten-free pastry, tucking the sides/ends under. Continue to wrap the remaining chicken breasts. Butter your casserole dish & line up the chicken roll ups in the pan, seam side down.
Bake at 350F degrees for 40 minutes. These can be made a day or two ahead of time, then just pop in the oven before your guests arrive (If you skip the step with the pastry sheets, you can try securing the chicken roll ups with toothpicks, and then remove them prior to serving).