Just a matter of chopping and mincing.
And stirring it together. I didn't add any lemon juice or lime juice to this. Just a little salt and let it sit while I cooked the fish. It produced plenty of juice. I had some cilantro in the fridge so I chopped some up and added that as well.
The other day I saw this jar of Tajin Seasoning at the grocery store. I had no idea what it tasted like! It said it had Chilis and lime, so I figured it would be good on fish. When I looked it up (after using it, not before--oh well!) it turns out that it is traditional to use on fruit, vegetables and in spicy drinks (or around the rim). It's very tart, and not that great just to taste out of the jar, but it really tasted great on the fish.
Nothing fancy about the fish prep (I used swai). Melt a small (less than a tablespoon) amount of butter over med-medium high heat. Season fish fillets generously, cook 3-4 minutes each side.
And serve the salsa over the fish. Really good and fresh.
I had some leftover salsa, so the next day I stirred in a little salad shrimp and added more cilantro, and that was good too!
Tomatillo and Tomato Salsa
1 medium onion, chopped
8 small (about 1-2 inches) tomatillos, finely diced
2 jalapeños, seeded, and finely diced
2 cloves garlic, minced
1 medium tomato, chopped
Salt to taste
Handful of cilantro, chopped
Fish with Tajin Seasoning
Swai Fillets
Tajin Seasoning
Butter
Melt a small amount of butter (for two fillets 1-2 teaspoons would be fine) over slightly over medium heat. Season the fish generously. When the better has bubbled and the bubbling is starting to subside, add the fish. 3-4 minutes each side should be fine.
Spoon the salsa over the fish.