Classic Burgers with Homemade Tomato Ketchup

• 1 Spanish onion, chopped
• 2 tablespoons olive oil
• One 28-ounce can whole tomatoes, including the puree
• 1/4 cup cider vinegar
• 2 tablespoons brown sugar
• 1 tablespoon tomato paste
• 1/2 teaspoon kosher salt
• 1/2 teaspoon freshly ground black pepper
• 1/4 teaspoon ground cinnamon
• 1/8 teaspoon ground allspice
• 1 1/2 to 1 3/4 pounds ground chuck
• 1 teaspoon kosher salt
• 1/2 to 1 teaspoon freshly ground black pepper

1. To make the ketchup:
2. 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.
3. Add the remaining ketchup ingredients, reduce the heat to low and cook, stirring occasionally, until very thick, about 35 minutes.
4. Set aside to cool.
5. If you want a chunky ketchup, cover and refrigerate.
6. For smooth, transfer to a food processor fitted with a steel blade and process to the desired texture.
7. Cover and refrigerate at least overnight and up to 3 weeks.
8. (Yield: about 2 cups)
9. To make the burgers:
10. Place the beef on a work surface and divide into 4 balls of equal size.
11. Form each into a patty about 3/4 to 1 inch thick by tossing it back and forth between your hands.
12. To ensure more even cooking, make a 1/2-inch indentation with your thumb in the center of the burger.
13. Handle the patties as little as possible; do not work more than necessary.
14. Prepare a grill to medium-high.
15. When the coals are glowing red, after 15 to 20 minutes, cover with the grate.
16. After 5 minutes, use a wire brush to thoroughly clean the grate.
17. Brush the grate with oil.
18. 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.
19. Sprinkle both sides of the burgers with the salt and pepper.
20. 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.
21. Transfer to buns or a serving platter and serve immediately.
22. Alternatively, place a cast iron skillet over high heat and when it is hot but not smoking add the burgers to the dry pan.
23. Cook until well seared on both sides, 8 to 10 minutes for medium rare or 10 to 12 minutes for medium.

onion, olive oil, tomatoes, cider vinegar, brown sugar, tomato paste, kosher salt, freshly ground black pepper, ground cinnamon, ground allspice, ground chuck, kosher salt, freshly ground black pepper

Taken from www.cookstr.com/recipes/classic-burgers-with-homemade-tomato-ketchup (may not work)