Preheat your oven to 190°C (375°F). Lightly grease a 9x13 inch (23x33 cm) baking dish with butter or cooking spray.

Cook the egg noodles according to package directions until al dente. Be careful not to overcook them, as they will continue to cook in the oven. Drain the noodles well and set aside.

While the noodles are cooking, brown the ground beef in a large skillet over medium-high heat. Break up the meat with a spoon as it cooks. Once browned, drain off any excess grease.

Add the finely chopped yellow onion to the skillet with the browned beef. Cook for 5-7 minutes, stirring occasionally, until the onion is softened and translucent. Add the minced garlic and cook for another minute until fragrant. Be careful not to burn the garlic.

In a separate medium saucepan, melt the butter over medium heat. Once melted, whisk in the all-purpose flour until a smooth paste forms. Cook this roux for 1-2 minutes, stirring constantly, to cook out the raw flour taste. This is the base for your cheese sauce.

Gradually whisk in the milk, a little at a time, ensuring each addition is incorporated before adding more. Continue whisking until the sauce is smooth and begins to thicken. Bring the sauce to a gentle simmer, stirring constantly. This should take about 5-7 minutes.

Reduce the heat to low. Stir in 150g (1.5 cups) of the shredded cheddar cheese until it is completely melted and the sauce is smooth and creamy. Season the cheese sauce with 1 teaspoon (5g) of salt, 1/2 teaspoon (2g) of black pepper, and 1 tablespoon (15ml) of Worcestershire sauce. Taste and adjust seasonings as needed.

Add the drained egg noodles and the cooked ground beef mixture to the cheese sauce. Stir gently to combine everything thoroughly. Ensure the noodles and beef are evenly coated with the sauce.

Pour the noodle and beef mixture into the prepared baking dish, spreading it evenly.

Sprinkle the remaining 50g (1/2 cup) of shredded cheddar cheese evenly over the top of the casserole. If using, sprinkle the breadcrumbs over the cheese for an extra crispy topping.

Bake in the preheated oven for 20-25 minutes, or until the casserole is heated through and the cheese on top is melted and lightly golden brown. The edges should be bubbly.

Let the casserole rest for 5-10 minutes before serving. This allows the sauce to set slightly and makes it easier to serve. Garnish with fresh chopped parsley, if desired.