I just about flipped when I saw this!! I gotta try it!
For the salsa
1½ cups rhubarb, diced
¼ cup red onion, minced
2 tsp. lime juice
¼ cup finely minced scallions
1 jalapeño, seeded and minced
2 tsp. honey
1 Tbsp. cider vinegar
¼ tsp. kosher salt
1/8 tsp. cayenne
Fill a medium bowl with ice and water; set aside. Fill a medium saucepan with water and bring to a boil. Add the diced rhubarb, blanch for 10 seconds, then scoop out with a slotted spoon into the ice water. Place red onion in medium bowl and drizzle with lime juice. Remove rhubarb from water batch and blot with towel to dry, then transfer to clean medium bowl. Add rhubarb to red onion and toss with scallions and jalapeño. Whisk vinegar with honey until combined, add to salsa mixture and season with salt and cayenne. Refrigerate.
For the tacos
¼ cup yellow cornmeal
3 Tbsp. olive oil
2/3 pound whitefish, skin removed, cut into 2-inch strips
1 large sweet onion, sliced thin
6 5-inch corn tortillas
1 Tbsp. chopped cilantro leaves
Heat oven to 200°F. Place the cornmeal in shallow bowl and season with salt and cayenne. Dredge the fish strips in the seasoned cornmeal. Add 3 Tbsp. oil to a large skillet and sauté the fish over medium heat, turning, until golden and crispy, one to two minutes per side. Remove to a heatproof dish, and place in the oven. Heat the remaining oil in the skillet. Add the onions and cook over medium heat, stirring, until golden brown and slightly caramelized.
Warm the tortillas in a cast iron skillet about 30 seconds on each side; hold in warm oven if necessary. When ready to serve, place two or three pieces of fish in the center of the tortilla, top with some of the caramelized onion and finish with about 2 Tbsp. of the salsa and a sprinkle of cilantro. Serve any remaining salsa alongside.