Melt the butter in a large skillet over medium heat. Add the thinly sliced onions and cook for 25-30 minutes, stirring occasionally, until they're deeply browned and caramelized. This slow cooking develops sweet, complex flavors that form the foundation of this dish. While the onions cook, you can prepare the remaining ingredients.

Increase the heat to medium-high and add the ground beef directly to the caramelized onions from Step 1. Break it up as it cooks for 5-7 minutes until no longer pink. Add the onion soup mix, salt, pepper, and garlic powder, stirring to combine and toast the seasonings for about a minute. Drain off any excess grease to keep the dish from becoming too heavy. I find draining the fat here prevents the final dish from tasting greasy, while still keeping all those flavorful browned bits.

Pour the beef broth and french onion soup into the skillet with the cooked beef mixture from Step 2, stirring well to combine. Bring the liquid to a boil over medium-high heat. This creates a rich, savory broth that will cook the pasta and develop deeper layers of flavor throughout the dish.

Add the egg pasta directly to the boiling broth from Step 3 and stir well to prevent sticking. Return to a boil, then immediately reduce heat to low, cover with a lid, and simmer for 10-12 minutes until the pasta is tender and most of the liquid is absorbed. The pasta will continue to absorb the flavorful broth as it cooks, creating a creamy, cohesive casserole.

Remove the skillet from heat and top the hot casserole generously with the fried onions. Let it rest for 1-2 minutes so the onions stay crispy rather than getting soggy from the steam. I always add the fried onions at the very last moment—this ensures they maintain their crunch and provide that signature textural contrast against the creamy pasta and rich broth. Serve directly from the skillet or transfer to a serving dish.