Instructions

1. Arrange an oven rack to 3 to 4 inches from the broiler element and heat the broiler. Line a rimmed baking sheet with aluminum foil.
2. Pulse 1 quartered medium shallot in a food processor until broken down into very small pieces, 4 to 6 (1-second) pulses. Add 1 1/2 pounds skinless salmon pieces, 1 ounce baby spinach, and 1/4 cup fresh dill fronds and pulse until coarsely ground, 8 to 10 (1-second) pulses.
3. Whisk 1 large egg in a large bowl. Transfer the salmon mixture into the bowl. Add 2/3 cup panko breadcrumbs, 1/3 cup crumbled feta cheese, 3/4 teaspoon kosher salt, and 1/4 teaspoon black pepper. Gently fold together with a flexible spatula until combined.
4. Divide the salmon mixture into 6 portions (3/4 cup or 5 1/2 ounces each). Form each one into a patty about 1 inch thick and 3 1/2 inches wide. Place on the baking sheet. Brush the tops with 1 1/2 teaspoons of the olive oil.
5. Broil until the patties are very lightly browned on top, 3 to 4 minutes. Flip the patties and brush with the remaining 1 1/2 teaspoons olive oil. Continue to broil until they are just cooked through and register at least 125°F on an instant-read thermometer, 2 to 4 minutes more. Garnish with chopped fresh dill and serve with lemon wedges if desired.