In a large pot of boiling, salted
water, cook the pasta until al dente.
Stir in the escarole and drain,
reserving 1 cup pasta cooking
water; return the pasta and escarole
to the pot.
Meanwhile, in a medium skillet,
heat the olive oil over medium-low
heat. Add the ham, garlic and
crushed red pepper and cook,
stirring occasionally, for 5 minutes.
In a medium bowl, beat together
the eggs, lemon peel, lemon juice
and half of the cheese. Whisk in
1/2 cup reserved pasta water. Stir
the egg mixture into the pasta and
cook, stirring, over low heat, until the
cheese is melted and the mixture is
creamy, 2 to 3 minutes. Stir in the
ham mixture and the remaining
1/2 cup reserved pasta water; season
with salt and pepper. Top with the
remaining cheese.