To prepare the filling, heat remaining 1 teaspoon olive oil in a large skillet over medium-high heat. Add Jennie-O Extra Lean Ground Turkey Breast and diced onion. Cook, breaking up the turkey, until onion is translucent and turkey is cooked through. Add garlic and cook until fragrant, just 30 seconds. Stir in red enchilada sauce and black beans. Spoon the mixture into the spaghetti squash shells and top each half with cheese. Bake for about 10 minutes, or until cheese is melted and bubbly. Top with cilantro and salsa if desired.