Note: macronutrients include the sauce, not the garnish
Breakdown for 1 of 6 chicken patties without spices: 90 calories, 2.5g fat, 0g carbohydrates, 15g protein, sodium 75mg
Place a carbon steel or nonstick skillet on medium heat. Once hot, add butter and allow it to melt. Add the onions stir. Once the onions start to turn somewhat brown, add the remaining ingredients and stir. You may need to adjust the heat of the pan if it is too hot. Stir and monitor for about 15 minutes, or until the onions have reduced in size and are completely caramelized.
Place ingredients for the chicken mince in a food processor and process until mixed and minced together. Depending on the size of your processor, you may need to do this in batches.
Add minced chicken to a bowl, along with all the spices. Do NOT add salt as the bouillon cube is already pretty salty. Use an ice cream scoop to evenly divide the meat.
Place a carbon steel or cast-iron pan/griddle on medium high heat. Once hot, spray with avocado oil.
Add a scoop of the meat to the pan. Place a piece of parchment paper directly on top of the chicken, then smash it down using the back of a heavy skillet, cup or flat surface.
Let it cook for about 2 – 3 minutes or until sear marks appear, then flip it over using a spatula to cook/sear for an additional 2 – 3 minutes, or until cooked through. Note: if you plan to have cheese, add it once you flip the burger. It is VERY important not to overcook these as they will be VERY dry due to the leanness of chicken.
Build your burger! Toast the buns in the oven, then add the sauce, lettuce, tomato, the smash burger patties, and caramelized onions.