1. Heat butter and oil in a medium sized pot. Once heated add in the diced onions. Saute for about 5 minutes or until translucent. Add in the garlic and saute for another 3 mins being careful not to burn.
2. Add in the russet and yukon potatoes, and then immediately add in the chicken stock. Season with about 1 tbsp of salt, pepper and red pepper to taste.. Bring to a simmer, and let cook for about 15 mins.
3. Once the potatoes are close to fork tender, add in the heavy cream and cream cheese. Simmer until the potatoes are all the way fork tender (about another 5 mins or so).
4. Use an immersion blender to puree the soup until you reach desired consistency. Taste for seasoning.
5. Garnish with cheddar cheese, crispy bacon, scallions, and sour cream!