Slice the potatoes by placing them (one at a time) in between 2 wooden spoons of kitchen utensils (see video for reference). This will allow you to more accurately slice the potatoes without slicing too far down to the bottom. Make very thin slices into the potato going all the way across. You want the slices to be roughly 1/4 inch thick each. Having a very sharp knife will make this easier.
4 russet potatoes
Place the potatoes, cut side up, on a rimmed baking sheet. Drizzle with olive oil and sprinkle with a little salt. Bake for 50 minutes.
1 tbsp olive oil
Meanwhile, in a small bowl, mix together the melted butter, salt, pepper, and garlic powder.
3 tbsp unsalted butter, 1 tsp fine sea salt, 1/2 tsp freshly ground black pepper, 1 tsp garlic powder
After 50 minutes, remove the potatoes from the oven and evenly distribute the slices of cheddar cheese into the cuts of the potatoes. I added a slice of cheese in roughly every 3rd-4th cut. Brush the tops of the potatoes with the butter mixture. Sprinkle with the parmesan cheese.
4 oz block of sharp cheddar, 3 tbsp Parmesan cheese
Bake for 15 more minutes. Top with chives and enjoy!
chives for garnish
Notes
Storing. To store your leftover hasselback potatoes, place them in an airtight container in the fridge for up to 4 days.
Reheating. You can reheat these in a microwave-safe dish for 1-2 minutes until they are heated through, or warm in a preheated oven at 350ºF for 6-8 minutes.