1. Put cauliflower in a microwave safe bowl with 1/2 cup water. Microwave 10-15 minutes, or until very soft.
2. In small saucepan, heat olive oil or butter over medium-high heat. Use a whisk to blend in flour. Mixture will become very thick.
3. Slowly pour in 1 cup vegetable broth. Continue whisking until smooth. Stir continually 1-2 minutes or until mixture is thick.
4. Combine flour mixture, potatoes, cauliflower, onion, garlic, and remaining broth in crock pot. Add salt and pepper if desired. Cook on low 10-12 hours, or high 6-8 hours.
5. Just before serving, cube cream cheese and microwave 1-2 minutes until very soft.
6. Scoop about 1-2 cups of potato chunks out of the crock pot, and set aside. (More if you like chunkier soup; less if you like smoother.) Make sure and leave all cauliflower chunks in the crock pot.
7. Add cream cheese to crock pot. Use an immersion blender to thoroughly puree; leave no chunks.
8. Stir remaining potato chunks back inches Serve. Top each bowl with 1 tbsp shredded cheese.
9. You can also top with bacon, chives, and sour cream, if desired.