In a large saucepan, fill it halfway with water or beef broth and bring it to a boil.
Once the broth is boiling, toss in your diced onions, chopped celery, and stewed tomatoes. Let the mixture return to a simmer.
If you’re using fresh corned beef, cook it separately until it’s tender, then chop or shred it. If you’re using canned corned beef, you can skip this step and add it directly to the soup later.
Stir in the Lipton Onion Soup Mix, along with any spices you prefer. Allow everything to simmer together for about 30 minutes, stirring occasionally.
Once the vegetables are tender and well-cooked, add the corned beef to the pot. Give the soup a good stir, and let it simmer for an additional 5-10 minutes.
Ladle it into bowls and serve hot.
