Gnocchi with Warm Sage Butter

Ingredients

• 2 medium Yukon Gold or russet potatoes
• 1/2 tsp kosher salt
• 2 tsp water
• 1 cup all-purpose flour
• 2 large egg yolks
• 1/4 tsp kosher salt
• 1/4 tsp freshly-grated nutmeg
• 1/8 tsp white pepper
• table salt (1 tsp per liter/quart of water)
• 4 tbsp unsalted butter
• 8 fresh sage leaves
• 1 large pinch kosher salt
• 1/4 cup grated Parmigiano-Reggiano (or to taste)