Ingredients

• 1/2 cup (1 stick) unsalted butter
• 1/4 cup bonito flakes
• 2 teaspoons dried shrimp
• 12 ounces fresh or dried capellini, tagliatelle, or fettuccine, preferably egg-enriched
• Kosher salt
• 2 tablespoons olive oil
• 1 red chile (such as Holland or Fresno), seeds removed, finely chopped
• 2 wide strips lemon zest, thinly sliced
• 1/2 pound rock shrimp or other small shrimp, peeled and deveined, cut into small pieces
• 1 tablespoon finely chopped tarragon
• 1 tablespoon fresh lemon juice
• 2 scallions, green parts only, thinly sliced
• A spice mill or mortar and pestle

Instructions

1. Melt butter in a small saucepan over medium-low heat, then add bonito flakes; swirl butter to combine. Remove from heat and let sit 10 minutes to infuse.
2. Strain butter through a fine-mesh sieve into a small bowl, pressing on solids; discard bonito flakes. Cover and chill butter until ready to use.
3. To assemble: Finely grind dried shrimp in spice mill or with mortar and pestle; set aside for serving. Cook pasta in a large pot of boiling salted water, stirring occasionally, until very al dente, about 3 minutes if using fresh pasta, longer if dried. Drain pasta, reserving 1 1/2 cups pasta cooking liquid. Meanwhile, heat oil in a large skillet over medium. Add chile and lemon zest and cook, stirring, 20 seconds. Add rock shrimp and cook, tossing, 1 minute. Add tarragon, lemon juice, pasta, 3/4 cup pasta cooking liquid, and 3 Tbsp. bonito butter and toss to coat. Cook, tossing and adding more pasta cooking liquid as needed, until sauce is glossy and coats pasta and shrimp are cooked through, about 3 minutes. Season with salt if needed. Divide pasta among bowls and top with scallions and reserved dried shrimp.
4. Finely grind dried shrimp in spice mill or with mortar and pestle; set aside for serving.
5. Cook pasta in a large pot of boiling salted water, stirring occasionally, until very al dente, about 3 minutes if using fresh pasta, longer if dried. Drain pasta, reserving 1 1/2 cups pasta cooking liquid.
6. Meanwhile, heat oil in a large skillet over medium. Add chile and lemon zest and cook, stirring, 20 seconds. Add rock shrimp and cook, tossing, 1 minute. Add tarragon, lemon juice, pasta, 3/4 cup pasta cooking liquid, and 3 Tbsp. bonito butter and toss to coat. Cook, tossing and adding more pasta cooking liquid as needed, until sauce is glossy and coats pasta and shrimp are cooked through, about 3 minutes. Season with salt if needed.
7. Divide pasta among bowls and top with scallions and reserved dried shrimp.