Step 1

Heat 1 Tbsp. oil in a large skillet over high heat. Working in batches, add brussels sprout leaves and cook, tossing occasionally, until charred in spots and crisp-tender, about 5 minutes; transfer to a plate and set aside. Wipe out skillet.

Step 2

Cook pasta in a large pot of boiling salted water, stirring occasionally, until al dente (about 5 minutes for fresh pasta). Drain, reserving 1 cup pasta cooking liquid.

Step 3

Meanwhile, heat remaining 1 Tbsp. oil in same skillet over medium heat. Add guanciale and cook, stirring often, until slightly crisp, about 4 minutes. Add pepper and cook, stirring, until fragrant, about 30 seconds. Immediately add ½ cup pasta cooking liquid to keep pepper from burning; reduce heat to low and gradually add butter, swirling skillet and adding more pasta cooking liquid as needed, until a thick, glossy sauce forms. (Taste as you go and switch to hot water once sauce is adequately seasoned.)

Step 4

Add pasta to skillet and toss to coat. Add Pecorino; toss to combine. Remove from heat; mix in egg yolks. Add reserved brussels sprout leaves; toss, adding pasta cooking liquid (or hot water) as needed to thin sauce.

Step 5

Serve pasta topped with more Pecorino.