Before starting, preheat the oven to 450°F. Wash and dry all produce. Add 10 1/2 cups water and 1 tbsp salt to a large pot (use same for 4 ppl). Cover and bring to a boil over high heat. Meanwhile, cut cauliflower into bite-sized pieces. Peel, then cut potato into 1-inch pieces. Peel, then mince or grate garlic. Peel, then cut half the onion into 1/4-inch pieces (whole onion for 4 ppl). Peel, then grate half the carrot (whole carrot for 4 ppl).

Heat a large non-stick pan over medium-high heat. When hot, add 1/2 tbsp oil (dbl for 4 ppl), then garlic, onions, carrots, peas and beef. Cook, breaking up beef into smaller pieces, until no pink remains, 4-5 min.** Stir in cornstarch, broth concentrate, 1/2 tsp salt and 1/2 cup water (dbl both for 4 ppl). Season with pepper. Bring to a simmer. Once simmering, reduce heat to medium. Cook, stirring often, until mixture thickens slightly, 3-5 min.

Meanwhile, add cauliflower and potatoes to the boiling water. Cook, stirring occasionally, until tender, 6-8 min. Reserve 1/4 cup cooking water (dbl for 4 ppl), then drain and return cauliflower and potatoes to the same pot, off heat. Roughly mash sour cream and 2 tbsp butter (dbl for 4 ppl) into cauliflower and potatoes until slightly creamy. (TIP: For a lighter consistency, add reserved cooking water 1 tbsp at a time, if desired.) Season with salt and pepper, to taste.

Transfer beef mixture to an 8x8-inch baking dish (9x13-inch for 4 ppl). Top with mashed cauliflower and potatoes, then spread into an even layer. Bake in the middle of the oven until mash is golden-brown on top, 18-20 min.

When mash is golden-brown, remove cottage pie from the oven and let stand for 5 min. Divide between plates.