Set a large nonstick skillet on the stove and place a plate nearby for the cooked salmon cakes. Set a medium bowl and a large bowl on the counter so the rest of the prep is easy to organize.

Cut the lemon in half. Finely chop the dill and celery, thinly slice the scallions, and thinly slice the cucumber.

Make the salad: Put the Greek yogurt in the medium bowl. Add 1 tablespoon of the lemon juice, about half of the lemon zest, half of the dill, 1/4 teaspoon of the salt, and a few grinds of black pepper.

Stir the yogurt mixture until smooth and evenly mixed.

Add the sliced cucumber to the medium bowl. Toss until the cucumber is coated, then set the salad aside while you make the salmon cakes.

Mix the salmon cakes: Put the drained salmon in the large bowl. Use a fork to break it into small flakes.

Crack the egg into the large bowl with the salmon. Add the panko, celery, scallions, Dijon mustard, the remaining dill, the rest of the lemon zest, 1 more tablespoon of lemon juice, 1/2 teaspoon salt, and a few grinds of black pepper.

Mix the salmon mixture with the fork until it looks evenly combined and holds together when you press a little of it between your fingers. If it feels very soft, let it sit in the bowl for 2 minutes so the panko can absorb some moisture.

Divide the mixture in the bowl into 4 equal portions. Shape each portion into a patty about 3/4 inch thick.

Cook the cakes: Pour the olive oil into the large nonstick skillet and set the skillet over medium heat. When the oil looks loose and lightly shiny, add the salmon cakes to the skillet in a single layer.

Cook the salmon cakes on the first side for 4 to 5 minutes. They are ready to turn when the bottoms are deep golden brown and the cakes release easily from the skillet.

Turn the salmon cakes with a thin spatula. Cook the second side for 3 to 4 minutes, until it is browned and the centers are hot.