Heat the olive oil and butter in heavy bottomed skillet over medium heat. Add the onions and carrots and saute until softened, 3-5 minutes. Stir in the garlic and cook until fragrant, 30 seconds. Add the flour and stir to coat the veggies. Cook until golden, another 2 minutes or so. Slowly stir in the half and half. The mixture will be very thick.

Add the chicken broth, nutmeg, and black pepper and cook for 6-8 minutes or until the soup is slightly thickened.

Stir in the broccoli and cook for an additional 8-10 minutes or until broccoli is softened. Use an immersion blender or transfer the soup to a blender in batches to puree the soup to the desired consistency. I like to leave lots of yummy broccoli chunks, but that's just me.

Return the soup to the pot (if needed) and stir in all but about 1/2 cup (or 2 ounces) of the cheddar cheese and all of the colby jack cheese. Stir until melted. Taste and season with salt and pepper if needed. Serve with the remaining cheddar cheese for garnish and good, crusty bread.