Hasselback Potatoes:

1. Preheat Oven: Preheat oven to 450°F (232°C).
2. Slice Potatoes: Place potatoes on a cutting board. Lay a butter knife on each side of a potato to prevent cutting all the way through. Make thin, evenly spaced slices across each potato.
3. Season and Roast: Place sliced potatoes on a baking sheet. Brush with olive oil, ensuring oil gets into the slices. Season generously with salt and pepper. Roast for 45-50 minutes, or until golden brown and crispy.
4. Caramelize Onions: While potatoes roast, melt 4 tablespoons of butter in a skillet over medium heat. Add sliced onions and a pinch of salt. Cook, stirring often, until translucent (about 10 minutes). Reduce heat to medium-low and continue cooking, stirring frequently, until deeply caramelized and golden (about 1 hour). Add a splash of water if onions become too dry.
5. Make Brown Butter: Once potatoes are done, melt 4 tablespoons of butter in a skillet (or the same skillet used for the onions after removing them) over medium-low heat. Cook, stirring occasionally, until butter browns and brown bits appear on the bottom. Remove from heat and stir for 30 seconds. Stir in minced garlic.
6. Assemble: Brush brown garlic butter over the roasted potatoes, ensuring it gets into the slices. Sprinkle with fresh herbs. Top with caramelized onions.
7. Serve: Serve immediately.