Cook the pasta in a large pot of boiling water. Cook until al dente and drain, reserving a 1/3 cup of pasta cooking water.
While the pasta is cooking, dice up the pancetta and grate the cheese. Slice the garlic.
In a large saute pan or wok, cook the pancetta over a medium flame. When the pancetta is crisp, toss in the sliced garlic and cook for 1 minute.
Turn down the flame and toss in the arugula. Quickly saute until soft with the pancetta. Add in the pasta with the reserved water and combine. Drizzle in the olive oil and the grated cheese and combine. The cheese and olive oil, when combined with the pasta water, thicken to coat the pasta, making the "sauce" for this dish.
Grind in some black pepper, add a pinch of salt, and at the very end, add in the shaved pecorino, reserving some for the top garnish.