In a sauté pan, over medium heat, heat the olive oil.
Add the carrots, celery, onion and garlic.
Sauté for 2 minutes until slightly softened and fragrant.
Add sautéd veggies to the crock pot.
Stir in the potatoes, salt, pepper, broccoli and chicken broth.
Set the crock pot to low for 6 hours or high for 4 hours.
After cooking time has expired, add milk; puree the soup using an immersion blender or spoon into a regular blender.
If using a regular blender, be very careful blending hot liquids and remember to vent the blender well.
The soup can be left as chunky as you like it or puree it entirely.
Once blended, stir in the cheese, adding it about a quarter of a cup at a time while stirring to avoid it clumping together.
Garnish with extra cheese, bacon and scallions prior to serving.