In a large, heavy sauté pan or medium pot, heat 2 tablespoons olive oil over medium heat.
Add the pancetta or chorizo and cook, stirring, for 2 minutes.
Add the onions and cook, stirring, until soft, 3 minutes.
Add the garlic, parsley, salt, pepper and red pepper flakes, and cook, stirring, for 1 minute.
Add the wine and clam juice and cook for 1 minute.
Add the clams, cover, and reduce heat to a simmer and cook for 5 minutes.
Add the cream and lemon juice, stir well, and simmer for 1 minute.