Rinse and check mussels, toss any cracked or dead ones. Remove beards by tugging back and forth and pulling out.
Pour beer into large pan that has a tight fitting lid. Add steak spice and bring to a simmer.
Pour in mussels and cover tightly. Turn heat to medium-high. Cook for 7 minutes. Check mussels, if they are open, they're cooked. Spoon liquid from bottom over mussels and serve hot.
Serve with crusty bread for sopping up juices.
Notes
If your mussels are smaller, check after about 5 minutes and continue to cook if not all are open.