Preheat oven to 400 degrees. Spray a baking sheet with non-stick spray.
In a medium skillet, heat butter or oil over medium heat.
If your shrimp is raw: removed tails if necessary and then season shrimp with Old Bay Seasoning, to taste. Saute shrimp 2 minutes on each side, until pink and cooked through. Remove and set aside.
If your shrimp is already cooked: remove tails, if necessary and then season with Old Bay Seasoning, to taste. Heat shrimp in skillet until hot, about a minute per side. Remove and set aside.
In same skillet add the bell pepper and onion sprinkle a little Old Bay Seasoning on the vegetables, to taste.
Cook just 2-3 minutes till softened a little. Remove from heat and set aside.
Unroll dough onto prepared baking sheet or pizza pan. Bake 5 minutes.
Remove partially baked crust from oven and spread Alfredo sauce over crust.
Lay the spinach on top of the sauce followed by the shrimp, bell pepper and onion mixture. Top pizza with mozzarella cheese.
Place pizza back into oven and bake 8 to 12 minutes longer or until cheese is melted and crust is browned.
Cut and serve.