Start by placing chopped turkey bacon in a cold skillet and bringing it to medium heat. Render the bacon until it is deeply browned and crispy, then drain it on paper towels.
Divide the ground beef into 4 equal patties, each weighing 1/4 lb. Use your thumb to create a dimple in the center of each patty to prevent doming while cooking.
Heat the avocado oil in a cast iron skillet until it shimmers. Sear the patties for 3-4 minutes on each side until charred grill marks appear.
In the last minute of cooking, add the cheddar slices on top of the patties. Cover with a lid to ensure a thick, gooey melt.
Toast the keto buns in the same pan. Begin layering with butter lettuce, followed by the cooked patty. Top with crispy turkey bacon bits, chopped green onions, and a drizzle of ranch sauce.
