A fresh tomatillo salsa doubles as the poaching liquid for firm-fleshed white fish, such as halibut or cod, served with zesty cilantro rice. This dish is light, but the crispy fried jalapeño slices add just the salty crunch needed on top!
Stir together the rice, 3 cups water, 1 tablespoon oil and a pinch of salt in a medium pot and bring to a boil over high heat. Cover, reduce the heat to low and cook until fluffy and tender, about 20 minutes.
Bring a large straight-sided skillet or saute pan filled with water to a boil over high heat. Add the tomatillos and cook until softened and slightly pale, about 4 minutes. Drain the tomatillos and put in a blender along with the onion, 1 jalapeno, garlic, cilantro stems and 1/2 teaspoon salt. Put the lid on the blender, leaving one corner open. Cover the lid with a kitchen towel to catch splatters, and pulse until smooth, about 1 minute. Pour the tomatillo salsa back into the same skillet or saute pan and set over medium heat.
Season the fish fillets on all sides with 2 teaspoons salt. Nestle the fish in the tomatillo salsa, cover and cook until the fish is opaque and there is no resistance when a paring knife is inserted, 6 to 8 minutes.
Reserve 1/4 cup loosely packed cilantro leaves for garnish and chop the remaining cilantro leaves to yield 1/4 cup.
When the rice is done, use a fork to fluff it, then stir in the lime zest, lime juice and the 1/4 cup chopped cilantro leaves. Season with 1/2 teaspoon salt. Keep warm.
Generously coat a small saute pan with oil and heat over medium high until shimmering. Add a pinch of flour to the oil. If it sizzles, the oil is ready for frying. Line a small plate with paper towels.
Thinly slice the 2 remaining jalapeños crosswise. Put the flour in a small bowl. Working in batches, coat the jalapeño slices in the flour, then fry on each side until the seeds are golden brown, 2 to 3 minutes total. Transfer to the prepared plate and season with a pinch of salt.
To serve, put a quarter of the rice on left side of a wide shallow bowl, spoon a quarter of the tomatillo salsa on the right side and use a spatula to carefully place 1 fish fillet on top. Repeat with the remaining rice, salsa and fish. Garnish with the reserved cilantro leaves and a fried jalapeño slices.
When blending hot liquid, first let it cool for five minutes or so, then transfer it to a blender, filling only halfway. Put the lid on, leaving one corner open. Cover the lid with a kitchen towel to catch splatters, and pulse until smooth.