Ingredients:
- 1 tbsp (15 ml) olive oil
- 1 large yellow onion, chopped (approx. 1 ½ cups, 150g)
- 2 cloves garlic, minced
- 1 lb (450g) ground beef (at least 80% lean)
- 1 cup (240 ml) beef broth (low sodium)
- 1 cup (120g) frozen peas
- 1 cup (120g) frozen corn
- 1 tbsp (7g) tomato paste
- 1 tsp (2.5g) dried thyme
- ½ tsp (1g) dried rosemary
- 1 tsp (5ml) Worcestershire sauce
- Salt and freshly ground black pepper, to taste
- 2 lbs (900g) sweet potatoes, peeled and cut into 1-inch cubes
- 4 tbsp (56g) unsalted butter
- ¼ cup (60 ml) milk
- Salt and freshly ground black pepper, to taste
- Optional: 2 tbsp grated Parmesan cheese (for topping)
Instructions:
- Boil the sweet potatoes until tender. Drain, then mash with butter and milk until smooth. Season with salt and pepper. Set aside.
- Heat olive oil in a large skillet over medium heat. Add onion and cook until softened. Add garlic and cook for 1 minute more.
- Add ground beef to the skillet and cook, breaking it up with a spoon, until browned. Drain off any excess grease.
- Stir in beef broth, peas, corn, tomato paste, thyme, rosemary, and Worcestershire sauce. Season with salt and pepper. Bring to a simmer and cook for 10 minutes, or until the sauce has thickened slightly.
- Pour the beef filling into the baking dish. Spread the sweet potato topping evenly over the beef filling.
- Bake in a preheated oven at 375°F (190°C) for 25-30 minutes, or until the topping is lightly browned and the filling is bubbly. If using, sprinkle Parmesan cheese over the top during the last 5 minutes of baking.
- Let the casserole rest for 5-10 minutes before serving.