Preheat the oven and prep the baking dish - Preheat the oven to 400°, Convection Bake setting. Oil the baking dish (or a lined baking sheet).
Prep the veg - Slice the peppers into 2-inch long strips. Thinly slice three of the garlic cloves and smash the other three cloves. Toss the peppers, garlic, and capers with olive oil, enough to coat.
Prep the fish - Gently rinse the fillet and pat it dry.
Assemble and bake - Lay the salmon, skin side down, on the baking dish, and scatter the garlic, capers, and peppers atop. Bake for 20-25 minutes.