Combine the potatoes, broth, chopped shallots, and garlic powder in a slow cooker. Cook on high for 3 to 4 hours or low for 6 to 7 hours.
When the potatoes are cooked and tender, change the heat setting to warm and add the sour cream, salt, and pepper. Use a potato masher or hand mixer to blend the potatoes. Add some extra broth to promote smoothness if desired.
When the potatoes are blended, stir in the arugula, and chives. Taste, adjust seasonings as needed, and mix in butter or more sour cream if desired. Enjoy warm!
To make vegan, skip the sour cream or use a vegan butter substitute.
I prefer to leave the skin on my potatoes, but you can peel them if you don't like chunks of skin.
You can make these up to one day in advance and store in the fridge. To reheat, put them back in the crockpot on low for 1 or more hours. You can also transfer them to a baking dish, cover with foil, and reheat for 30-45 minutes at 350 degrees F. Mix in butter, sour cream, or milk as needed to keep them moist.