Heat The Oil In A Large Skillet Over Medium-High Heat. Add The Bell Pepper, Onion And Garlic; Cook And Stir Until Limp. Reduce The Heat To Medium, And Stir In The Seasoned Salt, Rosemary And Ketchup. Simmer, Stirring Constantly, Until Slightly Brown. Mix In The Tuna, And Cook For About 5 More Minutes To Blend The Flavors Before Serving.