Cook farfalle in a large pot of boiling salted water, stirring occasionally, until al dente; drain, reserving 2 Tbsp. pasta cooking liquid.
Meanwhile, heat oil in a medium skillet over medium-high. Add shallots and 1/2 tsp. salt; cook, stirring occasionally, until tender, about 5 minutes (do not brown). Add ham, peas, and cream. Bring to a simmer and cook, stirring occasionally, until sauce is slightly thickened, about 5 minutes. Remove from heat; stir in lemon zest, 2 Tbsp. parsley, and 1/2 tsp. pepper.
Return pasta to pot. Toss with sauce and reserved pasta cooking liquid; season with salt and pepper. Divide among plates, then top with parsley and Parmesan and season with more pepper.
