Heat a skillet over medium-high heat. Add a large drizzle of olive oil.
Combine the blackening spice thoroughly in a small bowl. Coat the tilapia filets lightly with olive oil, then pack the blackening spice thoroughly onto the filets.
Cook the filets for 2 to 2 1/2 minutes per side in the hot pan with plenty of olive oil (too little, and the fish will stick to the pan).
Once the fish is done cooking, scrape out any remaining bits of spice and add more olive oil to the pan. Add the capers to the pan and cook for about 1 minute. Cover if necessary; the capers may splatter.
Remove the capers from the pan and assemble the salads: Chop the romaine lettuce and divide between two bowls. Add a few generous handfuls of cherry tomatoes to the bowls, then add one filet to each bowl. Top with the crispy capers and serve.