Ingredients

2 carrots, peeled into ribbons (about 2 cups) 

1 small cucumber, such as Persian, thinly sliced (about 1 cup) 

4 radishes, very thinly sliced (about 1 cup) 

1/4 cup unseasoned rice-wine vinegar 

2 teaspoons sugar 

Coarse salt and freshly ground pepper 

1/3 cup mayonnaise 

1 1/2 teaspoons Sriracha, plus more for serving (optional) 

2 skinless red-snapper fillets (each about 8 ounces) 

Extra-virgin olive oil, for brushing 

4 Portuguese rolls, halved 

1/2 cup lightly packed fresh cilantro leaves 

Preparation

Toss carrots, cucumber, radishes, vinegar, sugar, and 1/2 teaspoon salt in a bowl. Mix mayonnaise and Sriracha in another bowl.

Preheat grill to medium-high. Brush fish with oil; season with salt and pepper. Brush grates with oil. Grill fish until bottom edges turn opaque, about 3 minutes. Flip with 2 large spatulas and cook until opaque in center, about 3 minutes. Remove from grill; cut each fillet in half crosswise. Meanwhile, grill rolls until lightly marked.

Spread mayonnaise mixture on all roll halves. Layer fish and pickled vegetables on bottom halves; drizzle with pickling liquid and top with cilantro. Serve immediately, with more Sriracha.