• 27 russet potato, scrubbed and dried
• 13½ tbsp olive oil
• 6¾ tsp kosher salt
• 3⅓ tsp black pepper
• 27 tbsp butter, for serving, optional
• 0.4 l sour cream, for serving, optional
• 13½ tbsp chives, chopped, for serving, optional

Metric measurements are approximate conversions.