In a medium bowl, whisk together olive oil and tamari; season with salt and pepper. Add salmon and turn to coat. Marinate, refrigerated, at least 15 minutes or up to overnight.
Preheat oven to 425 degrees. Remove salmon from marinade; discard marinade. Place salmon on a baking sheet and roast until just cooked through, about 12 minutes. Let cool.
Remove skin from salmon and discard. Using your hands, break the salmon into large chunks.