How to Make It
In a food processor, pulse the salmon, scallions, eggs, bread crumbs, horseradish, ¾ teaspoon kosher salt, and ¼ teaspoon black pepper until coarsely chopped; form into 4 patties.
Cook the patties in the oil in a large nonstick skillet over medium heat until opaque throughout, 6 to 7 minutes per side.
Form sandwiches with the buns, mayonnaise, and lettuce. Serve with beet chips.