Heat olive oil in a 12-inch heavy skillet over moderately high heat until hot but not smoking.

Sauté chorizo and shallots, stirring, until chorizo is golden brown on edges, about 4 minutes.

Add garlic and sauté, stirring, 1 minute.

Add white wine and simmer until liquid is reduced by half, about 5 minutes.

Keep sauce warm, covered.

Cook pasta in a large pot of boiling salted water until al dente, then reserve 1 cup pasta cooking water and drain pasta in a colander.

Return pasta to pot and add sauce, mussels, parsley, cilantro, and 1/2 cup pasta cooking water.

Cook over low heat, stirring, until mussels are heated through.

Add more cooking water if pasta seems dry.

Toss pasta with lemon juice and salt and pepper to taste.

Serve immediately.