Can I use a whole egg instead of just the yolk?
Yes, but use one large egg and whisk it before tossing. The whites will be slightly less creamy than yolk-only, and cooking time needs to be watched carefully to avoid scrambling.
What if I don't have chili oil?
Mix 2 tbsp neutral oil with 1/2 tsp red pepper flakes and let it infuse for 5 minutes, or use sriracha thinned with oil for a different but complementary flavor.
Can this recipe be scaled for more servings?
Yes. Keep the ratios the same and increase all ingredients proportionally. For 4 servings, use 400g spaghetti and double the garlic, butter, and oils.
Is this dish vegetarian?
Yes, all ingredients are vegetarian. It is not vegan due to the butter, egg yolk, and Parmesan cheese.
Why use reserved pasta water?
Pasta water contains starch that emulsifies the oil and butter into a silky sauce and helps it coat the noodles evenly.