Mussels seem to benefit from garlic, and when steaming mussels you need a liquid of some kind to offset and augment the "liquor" which comes out of the cooking shellfish. Roasted garlic salsa fresca is just about right. Bring the salsa to a low boil, and add the de-bearded, scrubbed, mussels, simmer on low for 5 minutes. Before cooking, mussels that are open and obviously dead can be discarded, after cooking discard mussels that don't open. Again, exercise caution when using this ingredient. Here, we only do mussels, clams, oysters on the "r" months: September through April, but if the weather is still warm in September wait a month or two. As soon as human activity on the coast slows down, the shellfish are safer to eat. Salsa fresca can be made with ripe tomatoes, diced, onions, garlic, and cilantro.