Sometimes you just need a burger with everything on it and a pile of fries on the side. This is that dinner — high calorie, zero apologies.
Thoroughly wash and cut the russet potatoes into 1/2-inch fries, soak in cold water for 15 minutes to remove excess starch, then dry completely.
Preheat a deep pan with canola oil over medium-high heat (350°F); fry the potatoes in batches for about 5–6 minutes until golden and crispy, then drain on paper towels and season immediately with kosher salt.
Form ground beef into two 6-oz patties, season both sides generously with kosher salt and black pepper. Cook bacon in a large skillet over medium heat until crispy, then set aside on paper towels, saving 1 tbsp bacon fat.
In the same skillet over medium-high heat, cook beef patties in reserved bacon fat for 2–3 minutes per side; in the last minute, top each patty with two cheddar slices and cover to melt the cheese.
Lightly butter the interior of potato buns and toast in a separate pan over medium heat until golden. Assemble burgers: bottom bun, lettuce, patty with cheese, bacon, tomato, red onion, pickles; spread mayo, ketchup, and mustard on the top bun, then close. Serve immediately with hot fries on the side.