Make the burger sauce. Stir all the sauce ingredients together till smooth, taste and adjust any seasonings. Refrigerate till ready to use.
Heat a cast iron pan over high heat for at least 2-3 minutes to get it hot. If using a lower fat beef, add about 1-2 teaspoons of oil to the pan. Place ground beef into the hot pan, using a spatula to smash it down into the pan as thin as possible (this will get that nice burger sear). Sprinkle about 1/2 teaspoon kosher salt, black pepper, garlic powder, and smoked paprika on top of the beef.
Allow it to cook, undisturbed for 4-5 minutes until a crust forms on the burger. Flip and cook on the other side another 1-2 minutes. Breaking up the beef into bite sized pieces. Remove the ground beef from the pan and set aside.
With the same pan, turn the heat down to medium low and add the shallots, using the leftover juices from the beef to cook them. Stir occasionally till softened, about 4-5 minutes.
To large, flat bowls, add torn lettuce leaves, beef, shallots, American cheese, cherry tomatoes, and pickles. Drizzle the burger sauce on top.
Notes
Ground beef - 85/15 will give you the best flavor, but use any amount you like. If using a lower fat type, you may need to oil the pan before cooking. Ground turkey or chicken can also be substituted.
Shallots - I find shallots (fresh and dried) give the best flavor, but onion can be substituted if that's all you can find. Dried shallots are found in the bulk spice aisle or can also be found online.
American cheese - Boar's head or Andrew and Everett are good quality - typically found behind the deli counter. You can shred at home. If you want, melt this on top of the burger meat as it finishes cooking for the final 1-2 minutes in the pan.
HYH - Use shallots and onion-free ketchup, like Fody, or tomato sauce. Also a good quality mayo like Chosen Foods Avocado Oil mayo.