These turkey burgers with maple caramelized onions, which are perfectly moist and tender, are made with ground turkey, mustard, egg, garlic, and parsley, and are topped with cheese and sweet and spicy caramelized onions.
For the caramelized onions*
- About 2 tablespoons olive oil
- 2 large (8-ounce each) onions thinly sliced
- 3 tablespoons maple syrup
- 1/4 teaspoon cayenne pepper
- Sea salt and freshly ground black pepper
For the turkey burgers
- 1 1/2 pounds lean ground turkey
- 1 tablespoon whole-grain mustard
- 3 garlic cloves minced
- 1 large egg
- 2 tablespoons chopped flat-leaf parsley leaves
- 1/2 teaspoon sea salt
- 1/4 teaspoon freshly ground black pepper
- Extra-virgin olive oil for brushing
- 4 burger-size Cheddar cheese slices
- 4 store-bought or homemade burger buns split and toasted
Make the caramelized onions
- Heat the oil in a large skillet over medium-low heat. Add the onions and cook, stirring often, until they're softened and beginning to caramelize, 20 to 25 minutes. Add the maple syrup and cayenne and season with salt and black pepper to taste. Cook the onions, stirring frequently, until shimmery and translucent, another 7 to 10 minutes. Transfer the onions to a plate and cover to keep warm. (You can cool, cover, and refrigerate the maple caramelized onions for up to several days. Gently warm them in a covered saucepan over low heat just before serving.)
Make the burgers
- Meanwhile, place a grill pan over medium-high heat or preheat a gas or charcoal grill.
- Using your hands, in a large bowl mix the ground turkey, mustard, garlic, egg, parsley, salt, and pepper. Gently form the mixture into four 6-ounce patties, being careful to press the turkey mixture together enough so that the turkey burgers remain intact but not so much they become compact and hard as hockey pucks. Brush each side of each burger with olive oil and season with salt and pepper. (You can cover and refrigerate the turkey burgers for up to 24 hours before cooking. And actually, refrigerating them isn't just a convenient make-ahead trick, it actually helps the turkey burgers hold together better during cooking. So we highly recommend sliding them in the fridge, even for as little as 30 minutes.)
- Cook the turkey burgers, flipping them once, until cooked through, 12 to 15 minutes total. (If using a grill pan, you'll probably need to turn the heat down to medium at some point.) Place a slice of cheese on each burger, top with some of the maple caramelized onions, and use a spatula to slide the whole shebang to the waiting buns. (Any leftover maple caramelized onions can be covered and refrigerated for up to 1 month.)
*How do I know when my onions are caramelized?The difference between sautéed and caramelized onions is that caramelized onions have been cooked long enough that their natural sugars are coaxed out and everything starts to turn deeply golden brown and jammy. As you continue cooking them, some onions will start to break down, the color will be darker in spots, and you'll start to notice fond (spots of caramelized sugar and onion) on the bottom of the pan. You're done once you get to the point where there's not much moisture left and you've got a pile of deep brown, jammy onions—at least 30 minutes. Taste one to see, your onions should be sweet and velvety soft.
Recipe Testers' Reviews
Turkey burgers are a summer staple meal at my house. I often find turkey burgers a little dull, but these hit the flavor spot with the mix of onions, cheese, and a nice brioche bun. The maple caramelized onions were a great addition. I let the onions caramelize while I assembled and grilled the burgers—I love multi-tasking!
For the initial 25 minutes of caramelizing, I kept adjusting the heat until I got some good color on the onions. I found that closer to medium on my gas range worked better than low, but I kept a constant eye on them to prevent burning. After adding the maple syrup, the onions quickly darkened and appeared caramelized. The onions didn't stick to the pan and I could scrape up the nice fond from the pan. I used 94% lean ground turkey.
A tribute to healthier eating, these turkey burgers are easy to put together and make a delicious meal. The additional maple syrup adds an underlying and quite satisfying sweetness to the onions, but I must say I would be just as satisfied with onions caramelized without the addition of the syrup. Using a nonstick skillet helped ensure that nothing got stuck or burned. As the onions cook, they take on a beautiful color and I think some good advice would be to let them go as long as you can while preserving a deep caramel color, as they only get better.
I mixed the burgers while the onions were sautéing and opted to make them indoors on a grill pan. The 12- to 15- minute timing was spot-on, and the end product was delicious. My husband loved the mustard! Next time I'd play around with some other ingredients, like sautéed red peppers or spinach and a bit of feta. Really, these burgers are a good base for adding anything that suits you. These burgers could easily be prepped in advance—perhaps some chilling in the refrigerator would make them hold together just a bit better. The onions could be made days in advance and reheated in a skillet or the microwave.
Originally published October 7, 2015