- 1 Spanish onion, chopped
- 2 tablespoons olive oil
- One 28-ounce can whole tomatoes, including the puree
- ¼ cup cider vinegar
- 2 tablespoons brown sugar
- 1 tablespoon tomato paste
- ½ teaspoon kosher salt
- ½ teaspoon freshly ground black pepper
- ¼ teaspoon ground cinnamon
- 1/8 teaspoon ground allspice
- 1½ to 1¾ pounds ground chuck
- 1 teaspoon kosher salt
- ½ to 1 teaspoon freshly ground black pepper
- To make the ketchup:
- Place a large skillet over medium-high heat and when it is hot, add the onion and cook, stirring, until soft and golden, 7 to 10 minutes. Add the remaining ketchup ingredients, reduce the heat to low and cook, stirring occasionally, until very thick, about 35 minutes.
- Set aside to cool. If you want a chunky ketchup, cover and refrigerate.
- For smooth, transfer to a food processor fitted with a steel blade and process to the desired texture.
- Cover and refrigerate at least overnight and up to 3 weeks. (Yield: about 2 cups)
- To make the burgers:
- Place the beef on a work surface and divide into 4 balls of equal size. Form each into a patty about ¾ to 1 inch thick by tossing it back and forth between your hands.
- To ensure more even cooking, make a ½-inch indentation with your thumb in the center of the burger. Handle the patties as little as possible; do not work more than necessary.
- Prepare a grill to medium-high. When the coals are glowing red, after 15 to 20 minutes, cover with the grate. After 5 minutes, use a wire brush to thoroughly clean the grate.
- Brush the grate with oil. When the coals are covered with pale gray ash and you can leave your hand 5 inches above the fire for 2 to 3 seconds, the coals are ready.
- Sprinkle both sides of the burgers with the salt and pepper. Place the burgers on the grate and grill until well seared on both sides, about 5 minutes for medium rare or 6 minutes for medium.
- Transfer to buns or a serving platter and serve immediately.
- Alternatively, place a cast iron skillet over high heat and when it is hot but not smoking add the burgers to the dry pan. Cook until well seared on both sides, 8 to 10 minutes for medium rare or 10 to 12 minutes for medium.