Scrub and remove the beards of the mussels and soak in cold water to remove any grit or sand. Change the water a few times until its clear. Leave soaking in cold water while you prepare the pesto. The mussels should close up when gently pressed or once they are placed in the water. Discard any that stay open.

In a food processor pulse the garlic and walnuts together until crumbly, add in the lemon zest and juice and then the cilantro, basil and arugula. With the processor on mix for about one minute and then slowly add in the oil through the feed tube at the top. Stop after half of the oil is mixed in and scrape down the sides. Turn the processor back on and add in the rest. Taste and season with salt and pepper.

Bring 1 ½ cups of the wine to a boil in a large pot, strain the mussels from their water bath and place in the pot. Cover and let steam 3 minutes. Remove the lid and stir checking to make sure all the mussels have opened. If not steam another 1-2 minutes and then quickly removed them from the pot. Discard any that didn’t open. Add the rest of the wine and bring back to a boil, add in 1 cup of the pesto and stir until starting to thicken. Add the mussels back in and stir for 2 minutes. Transfer to bowls and ladle sauce over the top. Serve hot with toasted baguettes.