Step 1

Place a quarter of the salmon into a food processor with the mustard and puree until the mixture becomes a paste. Add the rest of the salmon, the shallots, panko crumbs and ranch seasoning mix and pulse until everything is well combined. Take care not to overmix; the smallest pieces of salmon should be about the size of a pea.

Step 2

Turn mixture out into a bowl and season with a bit of salt and pepper. Shape into four burgers and refrigerate for at least 15 minutes, up to a few hours.

Step 3

Place the butter in a 12-inch nonstick skillet set over medium-high heat. When the butter stops foaming, cook burgers for 2–3 minutes per side, turning once. Take care not to overcook.

Step 4

In a small mixing bowl, mash avocado and stir with the Ranch dressing. Place a burger on the bottom of each of four buns, and top with lettuce. Spread the other halves with the ranch avocado mixture and place on top to close the burgers. Serve immediately.