Tom's Cheddar Onion Chipotle Burgers

Tom's Cheddar Onion Chipotle Burgers

Ingredients

• Onions
• 1 pound red onions, cut crosswise into 1/3- to 1/2-inch-thick rounds
• Celia's Garlic Extra Virgin Olive Oil
• 3/4 teaspoon coarse kosher salt
• 1/2 teaspoon coarsely ground black pepper
• 2 teaspoons (or more) Celia's Traditional Dark Balsamic Vinegar
• Chipotle Ketchup
• 1 cup ketchup
• 1 1/2 teaspoons chopped chipotle chiles from canned chipotles in adobo
• 2 teaspoons (or more) Celia's Traditional Dark Balsamic Vinegar
• Burgers
• 2 1/4 pounds lean ground beef, elk or buffalo
• Coarse kosher salt
• 6 thick slices sharp cheddar cheese
• 6 large hamburger buns, split, cut, grilled
• 6 tomato slices
• 2 cups fresh spinach leaves

Directions

1. Prepare barbecue (medium-high heat):
3. For Onions
5. Arrange onion rounds on baking sheet. Brush with oil; sprinkle with 3/4 teaspoon coarse salt and pepper. Transfer onion rounds (still intact) to grill rack; close cover. Cook until grill marks appear, about 4 minutes per side. Reduce heat or move onions to cooler part of grill. Close cover; cook until onions are tender, about 10 minutes. Transfer to medium bowl. Toss with vinegar. Set aside and cover.
7. For chipotle ketchup
9. Mix ketchup, chiles, adobo sauce, and 2 teaspoons vinegar in small bowl. Season with salt and more vinegar, if desired. Cover and chill.
11. For burgers
13. Shape beef into six 1/2-inch thick patties. Sprinkle patties on both sides with coarse salt and pepper.
15. Mix onions in a bowl with olive oil, salt, pepper and vinegar. Set aside.
17. Toast buns on grill until golden brown. Remove buns and set aside.
19. Place burgers on grill. Close cover; cook burgers until bottoms start to darken and juices rise to surface, about 3-5 minutes. Turn burgers; cook to desired temp, about 3-5 minutes or so longer for medium-rare. Top with onions and cheese. Close cover; cook until cheese melts. (To insure food safety, check meat with a thermometer and heat interior of burger to a minimum of 165 degrees.)
21. Place muffin bottoms on plates; spread with ketchup. Top with burgers, tomatoes, spinach, and muffin tops. Serve, passing remaining ketchup separately.