1. Place pancetta in a large saute pan and cook over medium-low heat, stirring occasionally, until crisp, about 15 minutes. Using a slotted spoon, remove from pan and drain on paper towels. Set aside. Pour off all but 1 tablespoon of the fat.

2. Add butter to the fat in the pan. Add garlic, shallots, and sugar and season lightly with salt and pepper. Reduce heat to lowest setting, and cook, covered, until shallots are soft and transparent, about 15 minutes. Remove lid, raise heat to medium high, and cook, stirring constantly, until pan has deep golden-brown coating, about 10 minutes. Do not allow to burn.

3. Add the stock and simmer until reduced by one-third, stirring to loosen brown bits from bottom of pan, about 7 minutes. The sauce can be prepared up to this point several hours ahead and kept, covered, in the refrigerator.

4. Bring a large pot of water to a boil for the pasta. (Reheat the shallot mixture if it was prepared in advance.) If using, add cream to shallots and simmer for 2 minutes over high heat, until sauce thickens slightly. Keep warm. Coarsely chop all but a small handful of herbs.

5. Cook pasta according to package directions. Drain and return to pot. Add chopped herbs to sauce and cook for another minute. Season to taste with salt and pepper. Add pasta to sauce and toss together over low heat for 1 minute. (As pasta and sauce heat, fry remaining herbs in 1/2 teaspoon olive oil until crisp, for garnish.) Stir in pancetta and 1/2 cup of the grated cheese. Divide the pasta among 4 bowls. Garnish with fried herbs. Serve remaining cheese on the side.