Cook orzo according to package directions; rinse in cold water and drain. Transfer to a large bowl. Add basil and 1 tablespoon oil; toss to coat and set aside., In a large skillet, saute shallot in butter and remaining oil until tender. Add the diced tomatoes, oregano and garlic; cook and stir for 1-2 minutes. Add shrimp and sun-dried tomatoes; cook and stir until shrimp turn pink, 2-3 minutes., Transfer to a greased 5-qt. slow cooker. Stir in the orzo mixture, cheese and olives. Cover and cook on low for 2-3 hours or until heated through.