Whisk the finely grated zest from 1 medium orange, 1 large egg, 2 tablespoons of the harissa paste, and ¾ teaspoon kosher salt together in a large bowl.

Coarsely chop the white parts of 3 medium scallions and add to a food processor. Finely chop the scallion greens and reserve for garnish.

Add 2 tablespoons fresh cilantro leaves to the food processor and pulse until the scallions are broken down into very small pieces, 4 to 6 (1-second) pulses. Add 1 pound skinless salmon pieces and pulse until coarsely ground, 8 to 10 (1-second) pulses.

Add the salmon mixture and ⅔ cup panko breadcrumbs to the egg mixture. Gently fold together with a flexible spatula until combined.

Divide the salmon mixture into 4 portions (about ¾ cup or 5 ounces each). Form each one into a patty about 1 inch thick and 3 ½ inches wide.

Whisk ¼ cup orange juice, 3 tablespoons honey, and the remaining 1 tablespoon harissa paste together in a small bowl.

Heat 1 tablespoon olive oil in a large (12-inch) nonstick or cast iron skillet over medium heat until shimmering. Swirl so that the oil coats the bottom of the pan. Using a wide, flat spatula, gently transfer the patties to the pan and cook until golden-brown on the first side, 3 to 4 minutes. Flip the patties and cook for 1 minute.

Reduce the heat to medium-low and pour the sauce over the patties. Cook, spooning some of the sauce over the patties as they cook, until the sauce is thickened and the salmon is just cooked through, about 3 minutes. An instant-read thermometer inserted into the center of the salmon patties should register at least 125°F. Garnish with the scallion greens and chopped fresh cilantro leaves if desired.