Preheat oven to 350 degrees F. Toast the bread crumbs in a dry skillet over medium heat until browned and fragrant, about 1 minute. Transfer to a large mixing bowl and set aside. Add the olive oil, onions, garlic, oregano, salt, and pepper to the skillet and cook until onions are tender, about 8 minutes. Let cool slightly. Add the onions to the bread crumbs along with the meat, cheese, and Worcestershire sauce. Toss and mix gently. Add the eggs and stir to coat the meat completely.
Transfer to a foil-lined sheet pan and gently press into desired shape. Bake until an instant read thermometer registers 160 degrees F in the center of the loaf, about 45 minutes.
Tent the meatloaf with foil and let rest for 15 minutes while you make the gravy (or you can make the gravy while the meatloaf is baking).
Gravy: Cook the onions, garlic, and oregano in the olive oil and butter in a large skillet over medium-high heat until browned, about 6 minutes. Add the tomato paste and bay leaf. Stir until paste turns brick red and garlic is fragrant, about 3 minutes. Add the chicken broth and crushed tomatoes. Bring to a boil over high heat. Reduce heat to maintain a simmer and cook sauce until it thickens, about 5 minutes. Whisk in Parmesan cheese, vinegar, salt, and pepper. Discard the bay leaf and transfer the sauce to a gravy boat. Slice the meatloaf and serve with the gravy.