Finely chop the pancetta after removing any rind. Finely grate the Pecorino Romano cheese.
Beat the eggs in a medium bowl and season with freshly ground black pepper. Set everything aside.
Add salt to the boiling water, add the spaghetti, and once the water returns to a boil, cook at a constant high simmer until al dente.
Bruise the peeled garlic cloves lightly with the flat blade of a knife. While the spaghetti is cooking, heat a generous amount of olive oil in a large frying pan or wok over medium heat. Once hot, add the pancetta and garlic.
Fry for about 5 minutes, stirring frequently, until the pancetta is golden and crisp. Remove the garlic cloves with a slotted spoon and discard.
Reduce the heat under the pancetta to low. When the pasta is al dente, lift it directly from the water using tongs or a pasta fork and transfer it to the frying pan with the pancetta. Allow some pasta water to transfer as well, and do not discard the remaining cooking water.
Stir most of the grated Pecorino Romano into the beaten eggs, reserving a small handful for garnish.
Remove the pan with the spaghetti and pancetta completely from the heat. Quickly pour in the egg and cheese mixture. Toss and lift the pasta vigorously with tongs or a fork so the residual heat thickens the eggs into a creamy sauce without scrambling them.
Add a few tablespoons of the reserved pasta cooking water as needed to loosen the sauce until smooth and glossy. Taste and adjust seasoning with a pinch of salt if necessary.
Serve immediately, garnished with the reserved Pecorino Romano and an extra grating of black pepper.
