Preheat the oven to 425F.
Place the quinoa in a saucepan with water or broth and bring to a boil. Reduce heat, cover, and simmer for about 15 minutes or until the liquid is absorbed.
Remove from heat and let sit covered for 5 minutes, then fluff with a fork and cool slightly.
While the quinoa cooks, finely dice the tomatoes, cucumbers, red onion, chives, and dill. In a large bowl, combine the cooked quinoa, tomatoes, cucumber, red onion, chives, and dill.
Transfer the quinoa to a large bowl. Add the tomatoes, cucumbers, red onion, chives and dill, and stir to combine. Add the olive oil, lemon juice, honey, and salt. Stir until everything is evenly coated.
Pat the salmon dry and drizzle with olive oil. Season with kosher salt, brown sugar, and herbes de Provence.
Transfer to the oven and cook for 10–14 minutes depending on thickness, or until the salmon flakes easily with a fork (you can also air fry the salmon at 400°F for about 8–10 minutes).
To make the whipped feta, add the Greek yogurt, feta, olive oil, honey, and a pinch of salt to a food processor or blender. Blend until smooth and creamy.
To assemble, spread whipped feta onto plates or bowls, top with quinoa salad, and finish with the salmon. Garnish with extra dill, chives, or a squeeze of lemon if desired.