Preheat oven to 375°. Line a rimmed baking sheet with foil.
In a small bowl, stir together garlic, 2 tablespoons olive oil, Italian seasoning, 1 teaspoon salt, and ½ teaspoon pepper. Rub mixture all over pork.
In a large skillet, heat remaining 2 tablespoons olive oil over medium-high heat. Add pork, and cook for 3 to 4 minutes per side or until browned (do not clean skillet). Place pork on prepared pan.
Bake for 45 minutes or until a meat thermometer inserted in thickest portion registers 145°. Let stand for 10 minutes before slicing.
Meanwhile, to skillet, add onion and remaining ¼ teaspoon each salt and pepper, and cook over medium heat, stirring occasionally, for 15 minutes or until lightly browned. Sprinkle flour onto onions, and cook, stirring constantly, for 2 minutes. Whisk in chicken broth, and cook, whisking frequently, until thickened; whisk in Worcestershire. Serve gravy with pork. Garnish with rosemary and sage, if desired.
Recipe by Paula Deen Magazine at https://pauladeenmagazine.com/roasted-pork-loin-with-onion-gravy-recipe/