Cook the salmon: If using fresh salmon, bake or steam until just cooked, then flake with a fork. If using canned salmon, drain well and remove bones/skin if desired.
Prepare the mixture: In a large bowl, combine salmon, spinach, feta, onion, garlic, dill, lemon zest, lemon juice, egg, and breadcrumbs. Mix gently until combined — it should hold together when pressed. Add extra breadcrumbs if too wet.
Shape the patties: Form into 6-8 cakes, about 2 cm thick. Chill in the fridge for 15-20 minutes to firm up.
Cook until golden: Heat olive oil in a non-stick skillet over medium heat. Fry salmon cakes for 3-4 minutes per side until golden brown and crisp.
Serve & enjoy: Serve warm with a dollop of Greek yogurt sauce, a fresh salad, or tucked into pita bread for a Mediterranean wrap.
