How to Make It
Preheat oven to 500°F. Prepare cauliflower according to package directions; place warmed cauliflower in a fine mesh strainer. Use a rubber spatula to press out as much liquid as possible. Place drained cauliflower in a medium bowl; stir in 1 cup of the Parmesan. Set aside.
Heat a 10-inch cast-iron skillet over medium-high. Add beef to skillet, and cook, stirring occasionally, until half of the beef is browned, about 3 minutes. Add onion, carrots, and garlic to skillet; cook, stirring occasionally, until vegetables are tender and all beef is cooked through, about 8 minutes. Add tomatoes to skillet; stir until incorporated.
Whisk together broth and cornstarch in a small bowl. Stir cornstarch mixture into skillet. Add peas, Worcestershire, salt, and pepper to skillet. Cook, stirring occasionally, until thickened and peas are crisp-tender, 5 to 7 minutes.
Spread cauliflower mixture evenly over beef mixture in skillet. Top with remaining 1/4 cup Parmesan; sprinkle with paprika. Bake in preheated oven until golden, about 5 minutes. Remove from oven, and let stand 10 minutes before serving.