In a large soup pot or Dutch oven, sprinkle the ground beef with onion powder, garlic salt, and pepper and brown. Drain any excess fat. Remove the cooked ground beef from the pan and set aside.
Add olive oil, onions, carrots, and celery to the pot. Cook over medium-high heat until the vegetables are tender, stirring occasionally.
Stir in the Italian seasoning and ketchup, ensuring the ingredients are well combined.
Add the chopped potatoes to the pot and pour in the chicken broth. Bring the mixture to a boil, then reduce the heat to simmer. Cover the pot and let it cook until the potatoes are tender.
Once the potatoes are tender, return the beef to the pan stirring well to combine.
Stir in the milk and sour cream (or Greek yogurt). Continue to heat the soup over low heat until warm, but don't bring it to a boil.
Season the soup with extra salt and pepper to taste.
Serve hot with your favorite toppings.
Notes
Store any leftovers in an airtight container in the fridge and reheat on the stovetop.