Pan-Seared Ribeye Steak with Blue Cheese Compound Butter

2- inch thick ribeye steak (about 2 lbs)

good quality olive oil

unsalted butter

rosemary twig for garnish

rosemary twigs to flavor the cooking butter

Sea or kosher salt and coarsely ground black pepper

For the compound butter:

unsalted butter

fresh rosemary (finely chopped)

shallot (minced)

blue cheese (Gorgonzola, Roquefort, or Stilton)

Worcestershire sauce