Japanese Mentaiko Spaghetti (Pasta With Spicy Cod Roe and Butter Sauce)

Name: Japanese Mentaiko Spaghetti (Pasta With Spicy Cod Roe and Butter Sauce)
Cook time: 15 min
Total time: 15 min
Yield: 2
Ingredients: Kosher salt; 1/2 pound (225g) dried spaghetti; 1 1/2 to 2 ounces mentaiko (40 to 55g; about 2 small lobes), depending on how strong you want the flavor to be (see note); 1 1/2 tablespoons (20ml) light ( usukuchi ) soy sauce; 6 tablespoons (90g) unsalted butter, melted; Nori seaweed strips, for garnish