Step 1

Put a large pot of salted water on to boil.

Step 2

In a medium bowl, whisk together eggs and Pecorino Romano; set aside.

Step 3

Heat olive oil in a large Dutch oven or other heavy pot over medium heat. Add pancetta; cook and stir until the fat begins to render and the edges are starting to crisp, 6-8 minutes. With a slotted spoon transfer pancetta to a clean plate, leaving the fat. Increase heat to medium-high and add mushrooms to pot; cook and stir 8-10 minutes, or until the liquid has evaporated and mushrooms are golden brown (for optimal browning leave mushrooms undisturbed for last 1-2 minutes). Return pancetta to pot and stir to combine. Remove from heat.

Step 4

As soon as you add mushrooms to pot, add pasta to boiling water; cook according to package directions until al dente (firm to the bite). Scoop out and reserve 1 cup pasta water; drain pasta in a colander and transfer immediately to mushrooms and pancetta in pot and stir to combine.

Step 5

Whisking constantly, add a scant quarter cup of hot pasta water into the egg and cheese mixture to temper eggs. Pour tempered egg mixture over pasta and mushroom mixture in a steady stream, stirring constantly. Continue to stir until well combined, adding more pasta water as needed. Season to taste with salt and pepper and serve immediately, garnished with more Pecorino Romano if desired.