Heat the olive oil in a large pot over medium-low heat. Add in the onion and garlic with a big pinch of salt and pepper. Cook, stirring often, until softened - about 5 minutes. Stir in the cauliflower and potatoes.
Pour in the stock. Bring the mixture to a boil. Reduce it to a simmer, cover and cook until the cauliflower and potatoes are softened, about 10 to 15 minutes.
While the soup simmers, make the bacon. Heat the bacon in a skillet over medium-low heat. Sprinkle on the chipotle chili powder. Cook until the bacon is crispy and the fat is rendered. Remove the bacon with a slotted spoon and place it on a paper towel to remove excess grease.
Carefully transfer the cauliflower soup mixture to a blender. You can also use an immersion blender, but I like to use a regular high powered blender because it gets so silky smooth. Cover the blender with a towel and carefully blend until smooth.
Pour the mixture back into the pot and heat over low heat. Stir in the cream. Taste the soup and season with more salt and pepper - you most likely will need ½ to 1 teaspoon more of salt, maybe more depending on the flavor of your stock. Heat the soup until warm.
Serve in bowls topped with the chipotle bacon and fresh chives. YUM.