Bake the Potatoes: Preheat your oven to 400°F (200°C). Wash and dry the potatoes thoroughly. Prick each one several times with a fork, rub lightly with olive oil, and season with salt and pepper. Arrange the potatoes either straight on the oven rack or on a baking tray and let them bake for approximately one hour, or until fork-tender. Allow to cool just enough to handle safely.

Scoop the Flesh: Slice the top off each potato lengthwise and carefully scoop out the insides, leaving about 1/4 inch of flesh attached to the skins to keep them sturdy. Transfer the scooped potato flesh to a large bowl.

Prepare the Filling: Add butter, sour cream, chives, garlic powder, chicken bouillon paste, salt, pepper, and milk to the potato flesh. Mash with a potato masher, then mix with electric beaters until smooth. Be cautious not to overmix—doing so can make the potatoes gluey. Add a bit more milk if needed; the filling should be soft since it will firm up in the oven.

Fill and Top: Spoon the creamy potato mixture back into the potato shells, mounding it slightly. Sprinkle shredded cheddar cheese over each one.

Second Bake: Reduce the oven temperature to 350°F (175°C). Place the stuffed potatoes on a baking sheet and bake for 15 minutes, or until the cheese is melted and bubbly on top.

Serve: Let cool for a few minutes, then serve warm and enjoy!