To get started, line a colander with either a paper towel or nut milk bag and set it over a bowl. Add the Greek yogurt and allow it to strain over a bowl for 10-15 minutes. This step is optional, but makes for a very creamy sauce.
While your yogurt is straining, place your naan either in a 350 degree oven or in a toasted oven set at 350 degrees for 5-10 minutes, until warm and slightly toasted.
Once the yogurt is strained, add to a bowl and stir in goat cheese, lemon zest, and 2 tablespoons chopped dill. Season with salt and pepper. Set aside.
Assemble the flatbread. Spread yogurt sauce over naan bread. Top with smoked salmon, cherry tomatoes, red onion, and capers. Sprinkle reserved dill over flatbread and sprinkle with salt, pepper, and everything bagel seasoning, if using.