Step 1

Slice 4 Persian cucumbers lengthwise into planks that are about 3" long and 1/4" thick. Cut off the crown and the rounded bottom of 1 pineapple, creating two flat surfaces. Stand the pineapple up, then use your knife to cut away the skin, following the contours of the pineapple from top to bottom. Cut your pineapple in four long pieces, then remove the core. Cut the pineapple plank crosswise into short 1/4" pieces. Set aside.

Step 2

Peel and finely chop one 2" piece ginger and 4–6 garlic cloves. (You should have about 2 Tbsp. each.) Mix 1 Tbsp. finely chopped ginger, 1 Tbsp. finely chopped garlic, 1 tsp. ground turmeric, 2 Tbsp. fish sauce, ½ tsp. crushed red pepper flakes, and a pinch of kosher salt in a small bowl. Cut 1 lb. white fish fillets, preferably skin-on, into 4 equal pieces, then massage marinade onto fish to coat evenly. Place in a shallow bowl or dish. Let marinate in the fridge at least 30 minutes and, preferably, up to 2 hours.

Step 3

Meanwhile, make the nước chấm dipping sauce. Stir 1 Tbsp. sugar and 5 Tbsp. warm water in a small bowl until sugar is dissolved. Halve 1 lime and squeeze in the juice (use your hand or a fine-mesh sieve to catch the seeds). Add a pinch of red pepper flakes if you’d like it to be spicy, remaining 2 Tbsp. fish sauce, remaining 1 Tbsp. finely chopped ginger, and remaining 1 Tbsp. finely chopped garlic. Stir to combine. Set aside for serving.

Step 4

Remove fish from refrigerator. Heat 1 Tbsp. vegetable oil in a medium nonstick skillet over medium. Working in batches if needed, cook fish (start skin side down, if your fish has skin) until flesh is opaque all the way through, firm, and flakes easily with a fork, about 3 minutes per side. Transfer to a plate and flake into smaller pieces.

Step 5

To assemble rolls, working one at a time, dip 12 rice paper rounds in a clean shallow bowl or pan of hot water until pliable but not floppy, about 15 seconds. Lay flat on a large plate or cutting board and arrange a piece or so of torn tender lettuce, some tender herbs, a slice or two of the reserved cucumber and pineapple, and a few pieces of fish horizontally across the center of wrappers, leaving a 2" border on left and right sides. Fold left and right sides inward, then tightly roll wrapper starting at the side nearest you. If you’d like to make rolls with exposed fillings, simply fold in the left side of wrapper before adding fillings. Arrange fillings so that they overhang slightly on the left side, then fold in the right side and roll up. Repeat until all of the fish has been used (you should get 10–12 rolls). Serve with reserved nước chấm for dipping alongside.

Step 6

Alternatively, you can plate all of the components separately with a bowl of warm water for soaking the wrappers and let guests assemble their own.

Step 7

Do ahead: Nước chấm can be made 2 weeks ahead. Cover and chill.