Preheat oven to 425F and prepare baking sheet with cooking spray.
Finely chop the olives, sun dried tomatoes, breadcrumbs, oil, garlic, and mustard, by hand or using a food processor.
Make a 1.4 inch vertical slit in the top of each salmon fillet to within 1/4 inch of each end. Divide the filling and stuff the fish. Bake in the center of the oven for 10 minutes per inch of thickness. Garnish with fresh parsley or basil.