Prepare the potatoes: Peel the russets and cut them into roughly 1- to 1½-inch cubes so they cook evenly in the crockpot.

Load the crockpot: Place the potato cubes in the crockpot insert. Add the minced or smashed garlic, chicken broth, and 1/2 teaspoon of the salt. Toss gently to distribute.

Slow cook: Cover and cook on HIGH for 2 to 3 hours or on LOW for 4 to 5 hours, until the potatoes are fork-tender and easily mashable. Cooking time depends on your slow cooker and the size of the cubes.

Drain and return: Carefully drain any excess cooking liquid (reserve a little if you like a looser mash) and put the potatoes back in the crockpot on the warm setting.

Warm the dairy: In a small saucepan or microwave-safe bowl, warm the milk and butter until the butter is melted and the mixture is hot but not boiling. If using cream cheese, add it now so it softens and blends easily.

Mash to your preferred texture: Using a potato masher or ricer, mash the potatoes directly in the crockpot. Pour in the warmed milk-and-butter mixture a little at a time until you reach your desired creaminess. Stir in sour cream if using. Season with the remaining salt and black pepper to taste.

Finish and keep warm: Smooth the surface, sprinkle with chopped chives, and set the crockpot to the 'warm' setting if you’re serving later. If you plan to hold the potatoes for more than 2 hours, check occasionally and stir gently to keep them creamy — add a splash of warm milk if they thicken.