In a skillet over medium-high heat, cook ground beef and diced onion until browned (6-8 minutes). Add garlic and cook for 1-2 minutes. Drain excess grease.
Transfer the beef mixture to the crockpot or stockpot.
Add diced potatoes, chicken broth, frozen vegetables, basil, and parsley to the pot. Stir to combine.
For the crockpot, cook on low for 6-8 hours or high for 3-4 hours until the potatoes are tender. For stovetop, simmer for 30-40 minutes.
Whisk cornstarch with milk until smooth. Slowly stir the mixture into the soup and cook until thickened.
Stir in Velveeta cheese cubes and cook until melted and the soup is creamy.
Serve hot, garnished with parsley if desired.
Notes
This soup pairs wonderfully with crusty bread or a side salad. To adjust the consistency, add more milk or broth.