STEP 1 Heat oven to 450°F. On rimmed baking sheet, toss tomatoes, oil, coriander, cumin and 1/4 teaspoon each salt and pepper. Roast 12 minutes.
STEP 2 Season salmon with 1/4 teaspoon each salt and pepper and nestle among tomatoes. Reduce oven temperature to 425°F and continue roasting until tomatoes have begun to break down and are juicy, and salmon is opaque throughout, 8 to 10 minutes more.
STEP 3 Scatter half of scallions then kale over salmon and tomatoes; let sit 2 minutes.
STEP 4 Spread yogurt on flatbreads, top with salmon and vegetables, then sprinkle with feta and remaining scallion, if desired.
