Prep ingredients: Peel cucumber, then halved lengthwise, scoop out seeds with a spoon, and cut into ½-inch pieces. Cut tomatoes into ½-inch pieces. Peel and finely chop 1½ teaspoons garlic. Pick cilantro leaves, then finely chop stems, keeping leaves whole.

Make salad & garlic sauce: In a medium bowl, whisk together 1 teaspoon of the chopped garlic, 2 tablespoons oil, and 1 tablespoon vinegar. Add cilantro stems, tomatoes, and cucumbers, stirring to combine. Season to taste with salt and pepper. In a small bowl, stir together all of the sour cream and remaining chopped garlic. Season to taste with salt and pepper.

Toast pitas: Brush both sides of each pita lightly with oil. Heat a medium nonstick skillet over medium. Add 1 pita at a time to skillet and toast until lightly golden and warmed through, about 1 minute per side. Wrap pitas in foil to keep warm as you go. Reserve skillet for step 5.

Season salmon: Pat salmon flesh and skin very dry, then season both sides with salt and pepper. Season flesh side only with 1 teaspoon of the dried oregano per filet (2 teaspoons total).

Cook salmon: Heat 1 tablespoon oil in a reserved skillet over medium until shimmering. Add salmon, skin side down, and press firmly in place for 10 seconds with the back of a spatula. Cook, occasionally pressing gently, until skin is well browned and very crisp, and salmon is almost cooked through, about 5 minutes. Flip salmon and cook until just medium, about 2 minutes (or longer if desired).

Assemble gyros & serve: Serve pitas topped with salmon and some of the chopped salad. Drizzle with garlic sauce, then garnish with whole cilantro leaves. Pass any remaining chopped salad and garlic sauce at the table.