Place the halved potatoes in a large pot and cover them with cold water. Add a generous pinch of salt and bring to a boil. Reduce the heat to medium and cook for 10-15 minutes, until the potatoes are fork-tender. (Time will vary based on the size of your potatoes.)

While the potatoes cook, heat the sour cream, cream cheese, butter, heavy cream, garlic, salt, and black pepper in a small saucepan over medium-low heat. Stir until combined, then remove from heat.

Transfer the potatoes to a colander and drain well. While still warm, press the drained potatoes through a potato ricer back into the pot.

Gradually stir in the warm sour cream mixture until the potatoes are creamy. Gently fold in the chopped chives.

Adjust seasoning to taste, transfer to a serving bowl, and serve hot.