Make the spice rub for the fish by place the following in a food processor: chili peppers, garlic, shallots, fresh ginger, fresh turmeric, Roma tomatoes, coriander seeds, macadamia nuts, and 1/4 tsp kosher salt. For lemongrass, use a heavy knife to trim off the top two thirds and the very bottom. Peel off tough outer leaves, then bruise with something heavy like a rolling pin, a mallet, or a small pan. In a small sauce pan, heat 2 tsp canola oil over medium heat. Add lemongrass and cook, stirring frequently, until golden brown, about 5 minutes. Add to food processor with other ingredients and blend until smooth.Defrost tamarind paste. Stir tamarind into paste and cool.
Portion the fish into 6 oz filets. Evenly season the trout with the spice rub and 1 tsp kosher salt on all sides. Refrigerate overnight.
Make the soy ginger vinaigrette: Mix the water, soy sauce, rice wine vinegar, honey, ginger, and canola oil until well combined. Refrigerate until ready to use.
Make the cauliflower: Preheat oven to 450 degrees. Toss the cauliflower florets in a bowl with 1/8 tsp kosher salt, pepper, and olive oil until well combined. Spread the florets on a sheet pan and roast for 12-15 minutes until lightly browned. Toss cooked cauliflower n the soy ginger vinaigrette.
Cook brown rice according to package instructions.
Cut banana leaf into 9" square. Blanch or steam the leaves quickly to soften. Place each 6-oz filet in the center of a leaf, then enclose the fish by folding with the ribs on the top and bottom of fish, then fold in sides. Use a bamboo skewer to secure the ends together.
Steam the fish for about 5 minutes. Finish by grilling fish for 1 minute on each side, allowing the leaf to slightly char. Ensure internal temperature of fish reaches 145 degrees.
To serve, open the banana leaf and place on plate with fish on top. Arrange 1/2 cup brown rice and 1/2 cup cauliflower around the fish (on top of the banana leaf). Garnish with 1/2 oz pickled chiles, 1/2 oz fried shallots, 1 Tbsp cilantro, and 1 lime wedge.