1 pound catfish, tilapia, haddock or other white fish fillets (see Note), cut into 4 portions
1 tablespoon extra-virgin olive oil
1To prepare salsa: Cut the top and skin off pineapple, remove the eyes and core. Finely dice the pineapple (you will have about 4 cups diced pineapple) and place in a medium bowl. Add scallions, cilantro, lime juice, jalapeno and oil. Toss to mix. Season with ¼ teaspoon salt and pepper. Serve immediately or cover and refrigerate for about 1 hour to allow flavors to blend.
2To prepare fish: Combine flour, ½ teaspoon salt and ¼ teaspoon pepper in a shallow dish; thoroughly dredge fillets (discard any leftover flour).
3Heat oil in a large nonstick skillet over medium-high heat. Add the fish, working in batches if necessary, and cook until lightly browned and just opaque in the center, 3 to 4 minutes per side. Serve each portion of fish with about ¼ cup salsa each.
Make Ahead Tip: Cover and refrigerate the salsa (Step 1) for up to 1 day.
Catfish: Look for U.S. farmed catfish—it's sustainably raised in non-polluting inland ponds and fed a mostly vegetarian diet.
Tilapia: U.S. farmed tilapia is the considered the best choice—it's raised in closed-farming systems that protect the surrounding environment. Central and South American tilapia is considered a good alternative. Avoid farmed tilapia from China and Taiwan—where the fish farming pollutes the surrounding environment.
Haddock (Scrod): To get the best choice for the environment, ask for U.S. Atlantic “hook-and-line-caught” haddock—this method causes the least damage to the sea floor and has the least bycatch.