Cut cauliflower into 6 cups florets. Add to a large microwave-safe bowl with 1/4 cup water, salt, and pepper. Cover tightly with plastic wrap and microwave 5 to 7 minutes, until tender. Drain cauliflower. Add butter and stir into cauliflower to melt. Transfer mixture to a food processor with 2 tablespoons water, salt, and pepper. Puree until smooth, about 1 minute.
Preheat broiler. Meanwhile, in a 10" oven-proof skillet, heat oil on medium-high. Add onions and cook 4 to 6 minutes, until tender. Stir in garlic and cook 1 minute. Add beef and cook 6 to 8 minutes, until meat is browned and crumbled, using a spatula to break up meat. Remove from heat. Tilt pan and use a spoon to remove about half of the excess liquid from the meat.
To skillet, add mixed vegetables and red peppers. Cook on medium-high 1 to 2 minutes, stirring occasionally. Season with salt and pepper. Remove from heat and spread cauliflower puree over mixture. Place skillet in broiler until topping is golden, 3 to 5 minutes.
Hannaford fresh Magazine, September 2023