1. Preheat the oven to 450 degrees F.
2. Stir together the butter, olive oil, grated garlic, sea salt, red pepper flakes, lemon zest, and chives in a bowl.
3. Scoop the herb butter onto a piece of parchment paper or plastic wrap, roll into a log and twist the ends to close. Chill overnight, or until firm.
4. Once butter is firm, slice butter into thin slices, set aside.
5. Place a potato between the handles of 2 wooden spoons or 2 chopsticks. Slice the potato into thin slices, leaving 1/4 inch at the bottom unsliced; the spoon handles will prevent you from slicing the potato all the way through. Repeat with the remaining potatoes.
6. Put the potatoes on a baking sheet, add butter slices in between each potato slice making sure to get in between all the slices.
7. Bake until tender and crisp, 55 to 60 minutes. Half way through cooking brush potatoes with butter mixture.
