1 Bring a large pot of water to a boil. Quarter one of the lemons and add it to the pot.
2 Meanwhile, finely grate the zest of the remaining lemon and then juice the lemon. Coarsely chop the onion. Cut the mozzarella into 1/2 inch cubes.
3 In a medium skillet, warm the oil over medium-high heat until hot but not smoking. Add the onion and garlic and stir-fry until the mixture begins to brown, about 5 minutes.
4 Add the pasta to the boiling water and cook until al dente, 4 to 5 minutes, or according to package directions.
5 Meanwhile, drain one of the jars of artichokes. Add the drained artichokes and the second jar of artichokes with its liquid to the skillet. Cook, stirring frequently, until the artichokes are heated through, about 3 minutes.
6 Stir the sour cream and mozzarella into the skillet and remove from, the heat.
7 Drain the pasta and discard the lemon quarters. Toss the pasta with the artichoke mixture, lemon juice, lemon zest and parsley (if using).