Pat the rainbow trout dry with paper towels. Place trout on a foil-lined baking sheet and drizzle with 1 teaspoon olive oil. Season with salt and pepper.
Dice tomatoes into bite-sized pieces. Add to a medium bowl. Add 1 tablespoon olive oil, capers, red pepper flakes, and salt. Stir to combine.
Add tomato mixture to the baking sheet around the trout fillet. Place in the oven to bake for 10-12 minutes.
Remove from the oven and enjoy.
Notes
Cooking times may depend on the thickness of your trout. My trout was thin, so it cooked very quickly. Adjust cooking times as needed.
Because my trout was thin, I just baked it with the skin on and then ate it off the skin. I found this easiest to do!
I used 4 small campari tomatoes that were 5 oz total. However, you can use 2 roma tomatoes (just dice into 8 pieces) or cherry tomatoes (slice in half).