If using microwave: Add onion, tomatoes, 2 tsp. olive oil, 1/4 tsp. salt, and a pinch of pepper to provided tray in a single layer. Cover tray with a damp paper towel and microwave until tomatoes burst and onions are tender, 4-6 minutes. Carefully remove tray from microwave. Carefully press tomatoes to release juices, add beef and a pinch of salt, and stir to combine. Microwave until meat is heated through, 2-3 minutes. In a mixing bowl, stir 1 tsp. water and sour cream until combined. Wrap flatbreads in a damp paper towel and microwave until warmed through, 20-30 seconds. Place beef mixture in flatbreads and top with sour cream mixture, feta, and spring mix. Bon appétit!

If using oven: Preheat oven to 375 degrees. Add onion, tomatoes, 2 tsp. olive oil, 1/4 tsp. salt, and a pinch of pepper to provided tray in a single layer. Place tray on a baking sheet and bake in hot oven until tomatoes burst and onions are tender, 10-12 minutes. Carefully remove tray from oven. Carefully press tomatoes to release juices, add beef and a pinch of salt, and stir to combine. Bake again on baking sheet until meat is heated through, 8-10 minutes. Place flatbreads directly on oven rack and heat until warmed through, 2-3 minutes. Carefully remove tray and flatbreads from oven. In a mixing bowl, stir 1 tsp. water and sour cream until combined. Place beef mixture in flatbreads and top with sour cream mixture, feta, and spring mix. Bon appétit!