Wash hands with soap and water. Heat oven to 425 °F. Arrange rack in upper third of the oven.
Line rimmed baking sheet with foil. Place flank steak on baking sheet. Do not rinse raw meat.
Combine olive oil, lime juice, garlic, paprika, cumin, salt, and pepper in a small bowl. Pour marinade over steak and rub into both sides. Wash hands with soap and water after handling raw meat.
Spread cherry tomatoes and shallots over top of the steak and season with salt and pepper. Roast in oven until desired doneness, about 25 minutes for medium, or until internal temperature reaches 155 °F as measured with a food thermometer. Let rest for about 10 minutes, then slice and serve with melted tomatoes, shallots, and warm tortillas.