To make good fish tacos, make a radish salad and salsa verde and fill toasted tortillas with broiled tilapia, the salsa and the salad. Prior to making the salsa and salad, preheat the broiler with the rack set four inches from the heat.
To make salsa verde, puree in a blender 1 bunch of cilantro, 2 tablespoons of lime juice, 2 tablespoons of olive oil, 2 tablespoons of water and salt and pepper to taste.
Make the radish salad by mixing 2 tablespoons of lime juice with 1 tablespoon of olive oil, 4 ounces of thinly sliced radishes, 3 thinly sliced scallions, 1/2 minced jalapeno and salt and pepper to taste.
Prepare the fish by placing 1 1/2 pounds of skinless tilapia fillets on a baking sheet and seasoning them with 1/2 teaspoon of coriander and salt and pepper to taste. Broil the fillets for four to five minutes until they are opaque and break them into chunks.
Toast 12 6-inch corn tortillas using tongs over a gas flame for 30 seconds per side. Alternatively, wrap stacked tortillas in damp paper towels and microwave them on high for one minute. Assemble the tacos by filling the tortillas with fish and salad, topping them with salsa verde and folding them over.