Once water is boiling add pasta. Cook until al dente -- usually 1 to 2 minutes less than the recommended cooking time on the package. While the pasta is cooking, in a separate shallow pot add olive oil, turning the pot so the oil will coat everywhere. Once hot (oil should appear shiny but not quite smoking), add pancetta and stir occasionally until golden brown. When the pancetta is golden brown, add garlic and onions and cook until the onions become translucent.