Bring a large pot of water to a boil for the pasta.
Simmer the stock with saffron to steep the threads.
Heat a large, deep skillet over medium heat with 4 turns of the pan of olive oil. Add pancetta and a rounded teaspoon of coarse black pepper. Render pancetta 3 minutes then add asparagus, shallots, garlic and peas, and toss 2-3 minutes more. Add wine, reduce heat to low and let simmer.
In a mixing bowl, whisk the egg yolks with the saffron stock to temper then add cheese.
Cook pasta in liberally salted water to al dente.
Remove sauce skillet from heat and add parsley, hot pasta and egg mixture. Toss 1 minute and serve in shallow bowls.