In a stock pot, melt butter over medium heat.

Saute onion in butter until onions are translucent, about 3-4 minutes.

Stir in chicken broth, half and half, broccoli, carrots and celery. Bring to a boil then reduce heat and simmer for 10-15 minutes or until broccoli is soft and tender.

In a small bowl, whisk together milk and cornstarch. Pour the mixture into the soup pot and stir until soup starts to thicken 3-4 minutes.

Stir in pepper, garlic powder, thyme, nutmeg and salt.

I placed an immersion blender in the pot to blend it, but it's totally your call. I prefer it a little smoother.

Drop the heat to low and stir in Velveeta and cheddar cheese. Continue stirring until all of the cheese has melted.

Top each bowl of soup with a little extra shredded cheddar cheese and serve immediately. Enjoy!