1-First Step: Gather and prep your ingredients (Mise en place) Set out all ingredients and measure them before you start. Dice 3 cups of russet potatoes into about 1-inch pieces and dice 1 cup of carrots. Dice 1/2 cup yellow onion and mince 2 garlic cloves. Shred the cheddar cheese and have 1 cup sour cream measured. Preheating the oven to 400°F now saves time later. Having everything ready before you cook will make the process smooth and help prevent overcooking any component.

2-Second Step: Brown the beef and aromatics Heat a large sauté pan over medium heat. Add the 1 pound of lean ground beef and break it up with a wooden spoon. Stir in the 1/2 cup diced yellow onion and the 2 minced garlic cloves. Cook for 5 to 7 minutes until the beef is browned and the onion is softened and juices run clear. If you used a fattier beef, drain excess fat now to prevent an oily casserole. Taste a small bit of the beef mixture and adjust salt if needed.

3-Third Step: Make the creamy beef base Sprinkle 2 tablespoons all-purpose flour over the pan and stir for about 1 minute to cook off the raw flour taste. Slowly pour in 1 cup beef broth while stirring to avoid lumps. Add 1 tablespoon dried minced onion flakes, 1 teaspoon onion powder, 1 teaspoon garlic powder, 1 teaspoon Worcestershire sauce, 1/2 teaspoon salt, and 1/4 teaspoon black pepper. Stir for 1 minute as the mixture thickens. Remove the pan from heat, then mix in 1 cup shredded cheddar cheese and 1 cup sour cream until smooth and fully combined. This creates a velvety, savory filling that holds the casserole together.

4-Fourth Step: Combine with potatoes and carrots Transfer the meat and sauce mixture to a roomy baking dish (around 9×13 inches works well). Add the 3 cups diced russet potatoes and 1 cup diced carrots directly into the meat mixture. Stir gently to coat the veggies evenly with the creamy beef sauce. Make sure the potatoes are evenly distributed so they cook at the same rate. If you want to leave potato skins on, just scrub them well first; peeled potatoes also work fine.

5-Fifth Step: Top with cheese and cover Smooth the surface and top the casserole evenly with the remaining 2 cups shredded cheddar cheese. Cover the baking dish tightly with aluminum foil to trap steam and help the potatoes and carrots become fork tender without drying out the top.

6-Sixth Step: Bake and test for doneness Bake at 400°F for 30 to 35 minutes. Cooking time varies by oven and how cold the dish was when it went in. Check doneness by piercing a few pieces of potato and carrot with a fork; they should be tender and slip off the fork easily. If you assembled the casserole from cold (straight from the fridge), add 10 to 20 extra minutes of baking time letting the dish sit at room temperature for 30 minutes before baking reduces this extra time.

7-Final Step: Garnish and serve Remove the foil, switch the oven to broil for a minute or two if you want a browned cheese top, watching closely to prevent burning. Sprinkle 1 tablespoon dried parsley over the top for color, or use chopped fresh parsley if you have it. Let sit for 5 minutes before serving so the casserole firms up slightly and is easier to portion. Serve hot with a simple green salad or crusty bread for soaking up the sauce.