Heat a large deep skillet over medium heat. Add extra-virgin olive oil, 4 turns of the pan in a slow stream, red pepper flakes, garlic and anchovies and cook until anchovies melt into the oil. Add thyme and wine. Reduce wine 1 minute. Add clam juice or stock, clam juice will give the dish a stronger clam flavor, chicken stock will give it a buttery personality. Stir in clams and lemon zest. Drain pasta. Add to skillet and toss with sauce 2 to 3 minutes, until pasta is al dente and has absorbed some of the sauce and flavor. Add parsley, pepper and salt, to your taste and serve with bread for mopping up remaining juices.