Preheat An Oven To 375 Degrees F (190 Degrees C). Place The Salmon Fillet In A Baking Dish; Top With The Pineapple With Juice, Kale, Onions, And Capers. Drizzle The Olive Oil And Lemon Juice Over The Salmon. Season With The Salt And Black Pepper. Cover The Baking Dish With Aluminum Foil. Bake In The Preheated Oven Until The Salmon Flakes Easily With A Fork, About 25 Minutes.