Pound each of the 4 pieces of turkey out to about 1/4 inch.
Spread the cheese on half of one side of each turkey breast (one wedge per piece of turkey). Put 1/2 cup of spinach on top of the cheese, fold the breast in half and use toothpicks hold the turkey together and keep the filling in.
Season turkey with salt and pepper.
Heat the olive oil in a large skillet over medium heat.
Cook the turkey for a few minutes on each side, until browned.
Add the canned tomatoes, fennel seed and oregano (or any other spices you desire).
Let simmer approximately 10 minutes until turkey is fully cooked and most of the juice from the tomatoes has thickened.