Combine 1 1/2 cups water, the quinoa and 1/4 teaspoon salt in a small saucepan and bring to a boil. Reduce to a simmer and cook until just tender, about 12 minutes. Drain well in a fine-mesh sieve; let cool to room temperature.
Meanwhile, pat the fish skin dry with paper towels. Season the fish with the fennel seeds, salt and pepper. Drizzle 1 tablespoon olive oil in a large nonstick skillet. Add the fish skin-side down, place the skillet over medium heat and cook the fish, without moving, until it is almost cooked through and the skin is golden
brown, 15 to 20 minutes. Flip and cook 30 seconds on the other side.
Meanwhile, trim the top and bottom of the oranges using a paring knife. Remove the peel and pith with the knife, then slice the oranges crosswise into rounds, discarding any seeds.
Combine the orange juice, vinegar, shallot, 1/4 teaspoon salt and a few grinds of pepper in a large bowl. Let sit at least 10 minutes. Whisk in the remaining 2 tablespoons olive oil. Add the quinoa, orange slices, kale and sunflower seeds; season with salt and pepper and gently toss. Divide among plates and serve with the fish.