Sprinkle shrimp with seasoning. Melt butter with oil in a large nonstick skillet over medium-high heat. Add shrimp, and cook 2 minutes per side or until almost done. Remove from skillet and set aside.
Add onion, bell pepper, and garlic to skillet; cook 5 minutes or until vegetables are tender. Add tomato paste; cook, stirring, 2 minutes. Add diced tomatoes and capers; cook until mixture is slightly thickened. Return shrimp to skillet and cook until shrimp are done.
Stir in oregano and sprinkle with cheese. Serve over Crispy Polenta Cakes recipe.