Heat oven to 450 degrees F.
in half horizontally and section it as you would a grapefruit
; do this over a bowl to capture all its juice. Remove seeds and combine flesh and juice in bowl. Repeat with grapefruit and lemon
. Stir in cilantro
, chopped habanero, and salt.
Put oil in a nonstick or cast-iron skillet over medium-high heat. A minute later, add fish
, skin-side down; season top with salt. Cook until skin begins to crisp
, 3 or 4 minutes, then transfer to oven. Cook another 3 or 4 minutes, or until a thin-bladed knife meets little resistance when inserted into thickest part of fish. Serve fish with Mayan citrus salsa