Two thin hamburger patties, brushed with mustard; loaded with pickle slices, deeply caramelized onions, a creamy sauce spiked with my Whole30 ketchup recipe, coconut aminos, and relish; all sandwiched between two perfect iceberg lettuce "buns".
Prep 15 minutesminutes
Cook 1 hourhour
Total 1 hourhour15 minutesminutes
Recipe Makes (Approximate): 2double burgers
Equipment
Small bowl
Large non-stick skillet
Large cast-iron skillet
parchment paper or aluminum foil to wrap burgers
Ingredients
For the Sauce
½cupWhole30-compatible mayonnaise(store-bought or make your own, see Notes)
3tablespoonsWhole30-compatible ketchup(store-bought or make your own, see Notes)
Combine mayonnaise, ketchup, dill relish, coconut aminos, vinegar, and maple syrup (only if not on Whole30) in a small bowl. Stir well to combine, then place in refrigerator to chill while you continue cooking.
For the Lettuce "Buns"
Slice off the stem of the head of iceberg lettuce, about ½"-¾” from bottom. Cut into fourths: down the center, then slice each half in half to make wedges. Take out the middle ⅔ of each iceberg wedge, so it leaves just a ¾” thick lettuce “bun”. Set aside.
For the Burgers
Heat 2 teaspoons avocado oil in a medium skillet (preferably non-stick) over medium-high heat until oil is shimmering. Add onions and ¾ teaspoon salt. Reduce heat to medium-low, and cook, stirring occasionally until onions are browned, about 15 minutes.
Once onions are browned, they will start to sizzle and look dry. Add 1 tablespoon water to skillet and stir, cooking until water evaporates and onions begin sizzling again. Repeat the process with 1 tablespoon water until onions are dark brown and extremely caramelized, about 3 times, a total of about 30 minutes. Transfer to a bowl and let cool.
Shape ground beef into four 2-ounce patties that are very thin and very wide, about ¼" thick and at least 4" wide. Season patties with plenty of salt and pepper.
Heat remaining 1 teaspoon avocado oil in a large cast-iron skillet over medium-high heat. Swirl the oil around the pan to coat with a thin layer. When the oil is very, very hot, add burger patties. Spread 1 tablespoon mustard on the top, raw side.
Cook patties, without moving, until they're very well browned and a bit crusty on the bottom, about 2-3 minutes. Flip patties so the mustard side is down and cook 30 seconds to 1 minute.
Assemble the Burgers
Spread 1 scant tablespoon of sauce onto inside of one lettuce "bun" (one lettuce quarter).
Top lettuce quarter with 2 pickles, then add 1 tomato slice.
Top tomato slice with 1 burger patty, then add 1 tablespoon of caramelized onions. Feel free to add more if you like.
Add second burger patty, then another 1 tablespoon caramelized onions.
Top with another scant tablespoon sauce, then add 2 more pickles and cover with top lettuce "bun". Wrap in parchment paper or aluminum foil.
Repeat to assemble second double burger and serve.
Recipe Notes
This recipe makes enough caramelized onions and sauce to serve on top of some homemade sweet potato fries or hash. You will have extra besides what you need for the burgers.
Maple Syrup: Note that you MUST omit the maple syrup in the sauce for this recipe to be Whole30!
Make it Keto: Omit all coconut aminos and maple syrup; instead, sweeten the sauce with a maple-syrup flavored keto liquid sweetener. You'll also need a keto-friendly ketchup (store-bought or make your own with my keto ketchup recipe).
Recipe yields 2 burgers, each with 2 patties Actual number of servings will depend on your preferred portion sizes. You won't use all of the caramelized onions or sauce on your burgers.