Note: Before cooking, discard any mussels that have cracked or open shells.
1 Tbsp. olive oil
2 shallots, halved and thinly sliced
4 cloves garlic, thinly sliced
1/4 tsp. crushed red pepper flakes, or to taste
2 lbs. mussels, cleaned and debearded if needed
1 pint grape tomatoes, halved
8 oz (1 cup) IPA-style beer
1 tsp. minced fresh thyme or 1/4 tsp. dried
1/4 cup chopped fresh cilantro
2 Tbsp. fresh lime juice
1/4 tsp. freshly ground black pepper
1 Tbsp. unsalted butter