Fill a large sauce pan with water and over high heat, bring to a rolling boil. Add brussels sprouts and blanch for 2 minutes.
You start the timer for 2 minutes when you put the sprouts into the boiling water. The water does not have to boil again. Stir while blanching to evenly cook. Drain in a colander to remove water from outsides.
Have your melted butter ready into a skillet. Once veggies are drained add cheese, salt, Old bay and black pepper. Stir in drained brussels sprouts and mix evenly to coat. Cook for 2-3 minutes, string frequently until fork tender to your liking.