Red rice is a short-grain, nutty-tasting type; you can use short-grain brown rice in its place.
- 1 small fennel bulb, very thinly sliced
- ¼ medium red onion, thinly sliced
- 3 tablespoons fresh lime juice, divided
- ½ cup cilantro leaves and finely chopped tender stems
- Kosher salt and freshly ground black pepper
- Toasted pistachio oil or almond oil (for serving; optional)
Cook rice according to package directions. Spread out on a rimmed baking sheet; let cool.
Meanwhile, toss fennel and onion with 2 Tbsp. lime juice in a large bowl and let sit, tossing occasionally, until lime juice is almost entirely absorbed, 10–15 minutes.
Coarsely chop ⅓ cup pecans; finely chop remaining nuts. Cook in olive oil in a small saucepan over medium-low until golden brown, 5–10 minutes. Let cool.
Add rice and pecans to fennel mixture along with remaining 1 Tbsp. lime juice and toss to combine. Gently fold in cilantro; season with salt and pepper. Serve drizzled with pistachio oil, if desired.
__DO AHEAD:__Rice salad (without cilantro) can be chilled up to 1 day. Bring to room temperature before serving.