Step 1

On a 6-quart Instant Pot, select More/High Sauté. Add 1 tablespoon of oil and the pancetta. Cook, stirring occasionally, until well-browned and crisp, 5 to 6 minutes. Using a slotted spoon, transfer to a paper towel–lined plate; set aside. Add the garlic and pepper flakes, then cook, stirring, until fragrant, 30 to 60 seconds. Pour in the wine and cook until most of the liquid has evaporated, 7 to 9 minutes. Add the tomatoes and cook, stirring occasionally, until they begin to stick to the pot, about 8 minutes. Add the reserved tomato juices and 4 cups water; stir to combine, then distribute the mixture in an even layer. Add the pasta, placing the strands horizontally so they lay flat, then press them into the liquid until submerged. Set the pecorino chunk on top.

Step 2

Press Cancel, lock the lid in place and move the pressure valve to Sealing. Select Pressure Cook or Manual; make sure the pressure level is set to High. Set the cooking time for 3 minutes. When pressure cooking is complete, quick-release the steam by moving the pressure valve to Venting. Press Cancel, then carefully open the pot.

Step 3

Select More/High Sauté. Cook, stirring to incorporate the melted pecorino, until the pasta is al dente and most of the liquid has been absorbed, 3 to 4 minutes. Press Cancel to turn off the pot. Using potholders, carefully remove the insert from the housing. Let stand for 5 minutes. Stir in the remaining 2 tablespoons oil, the pancetta and 1 teaspoon black pepper. Taste and season with salt. Serve with grated pecorino.