Spray saucepan with cooking spray and place over medium-high heat. Combine onion, celery, garlic and ground beef in saucepan. Cook until beef is browned. Drain if necessary.
Add 1/2-1 cup chicken broth and bring to a slow boil. Cover and reduce heat to low until onion and celery are tender, stirring occasionally and adding additional broth if necessary - about 10-15 minutes.
Once onion and celery are tender, add remaining chicken broth and heat until just boiling.
Reduce heat to medium-low, add evaporated milk and cubed reduced fat Velveeta cheese stirring continuously until milk is heated through and Velveeta is melted.