Tahini Bucatini

Ingredients

• 1/2 cup tahini
• 1/2 cup soy sauce
• 2 tablespoons rice wine vinegar
• 2 teaspoons toasted sesame oil
• 3 cloves garlic, crushed
• 1-inch pieces ginger, pealed and roughly chopped
• 1/4 cup cilantro stems, roughly chopped
• 1 tablespoon sriracha, or more to taste
• 1/4 cup starchy pasta water or more if needed
• 1 pound dried bucatini
• Toasted sesame seeds, chili flakes, cilantro, and scallions for garnish