Preheat oven to 375 degrees
Heat a 12-inch ovenproof skillet over medium-high heat. Add beef, onion, and garlic; cook, stirring often to crumble, until the beef is browned and onion is tender, 8 to 10 minutes.
1 lb Ground beef, 1 ea Large onion, chopped, 4 cloves Garlic, minced
Stir in tomatoes, Worcestershire, rosemary, 1 tablespoon parsley, 1 teaspoon pepper and 1/4 teaspoon salt.
15 oz Diced tomatoes, drained, 1 Tbsp Worcestershire sauce, 1-1/2 tsp Fresh rosemary, chopped, 1 Tbsp Fresh parsley, chopped, 1-1/2 tsp Black pepper, divided
Whisk broth and flour in a small bowl; stir into the mixture in the skillet.
1/4 cup Beef broth, 1 Tbsp Flour
Cook over medium-low heat, stirring often, until the mixture thickens, about 15 minutes.
Cook the mashed cauliflower for about 10 minutes. Drain. Add butter, cream, and the remaining 1/2 teaspoon salt; mash with a fork or potato masher until smooth.
4 cups Mashed cauliflower, 6 Tbsp Butter, 1/4 cup Heavy cream
Carefully spoon the mashed cauliflower over the hot mixture in the skillet, gently spreading it over the top (do not mix the 2 layers). Sprinkle with the remaining 1/2 teaspoon pepper.
Bake until the top is beginning to brown and the filling is bubbly, 22 to 25 minutes. Sprinkle with the remaining 2 tablespoons parsley before serving.
2 Tbsp Fresh parsley, chopped