Mince the onion, green bell pepper, and garlic.

Heat olive oil in a pan over moderately-low heat.

Add the minced onion, green bell pepper, and garlic to the pan.

Cook, stirring occasionally, until the onion is softened.

Shell and devein the shrimp.

Add the shrimp to the pan.

Cook the mixture over moderately-high heat, stirring, for 3 minutes, or until the shrimp are cooked through.

Stir in Worcestershire sauce and cayenne pepper.

Cook grits according to package directions.

Stir butter into cooked grits until melted.

Spoon hot grits onto a platter.

Top with butter.

Arrange shrimp mixture around and over grits.