Preheat oven to 425F. Place potatoes on a baking sheet. Brush each with olive oil, sprinkle with salt, and prick with the tines of a fork. Bake for 45-60 minutes or until fork tender. Lower oven temperature to 350F.

Meanwhile in a large hot skillet, add the beef, onion, and ½ teaspoon salt and cook until the beef is browned, breaking it into pieces with a spatula as it cooks, about 5-8 minutes. Drain off any excess grease.

Add the garlic and cook 60 seconds. Add the tomato sauce, broth, Worcestershire sauce, and vegetables then bring to a boil.

Once boiling, turn down the heat down to simmer and cook until the mixture is thick and glossy, about 15-20 minutes. Stir in the rosemary then taste and adjust for salt if necessary.

Once the potatoes are done cooking, cut in half lengthwise. Scoop out the insides into a large mixing bowl leaving a ¼ inch border, being careful not to tear the shell. Place the hollowed potato shells back onto the baking sheet.

With an electric mixer on very low speed or by hand with a potato masher, mash the cooked potato insides until mashed and smooth. Beat in the butter and remaining ¼ teaspoon salt until completely incorporated then slowly beat in the milk. Stir in ¼ cup cheese. Taste and adjust for salt if needed.

Divide the meat mixture among the potato shells. Top with mashed potatoes then sprinkle with the remaining 2 tablespoons cheese.

Bake at 350F for 18-20 minutes or until golden brown and cheese has melted.