Add the ground beef to a large dutch oven or soup pot and cook over medium heat until the beef is browned, stirring and breaking the meat into small pieces.
Drain the browned meat into a colander.
Using the same pot, add the onion and fresh carrots. Cook for 5 minutes, stirring occasionally until tender.
Add the garlic and cook, stirring, for additional minute.
Add the broth, stirring and scraping the bottom of the pot with a wooden spoon.
Add the ground beef, half-and-half, potatoes, and ground sage and stir to combine well.
Bring to a boil and cook for 5 minutes.
Then add the frozen corn and peas and cook for an additional 10 minutes.
In a small bowl, mix the cheese and cornstarch together and then add it the soup in small batches, stirring constantly until the cheese has melted completely.
Season with salt and pepper to taste.