In a medium bowl, combine the water, sake, sugar, salt, ginger, and peppercorns. Stir until the salt and sugar have dissolved; the liquid should taste like sweet seawater. Place the fish in a salmon poacher. Pour the liquid over the salmon, cover, and allow to brine, refrigerated, about 1 hour.
In a food processor, combine the mustard, wasabi paste, garlic, and vinegar. While the processor is running, slowly drizzle in the canola oil until an emulsion is formed. Remove the mayonnaise-like mixture from the processor and place in a non-reactive stainless steel bowl. Fold in the cucumbers, scallions, and cilantro, season with salt and pepper and refrigerate until ready to use.
Remove the salmon from the poacher and thoroughly clean the poacher. Place 2 over-turned ramekins on either side of the inside of the poacher. Line the interior of the poacher, up to the rim, with foil. Make sure that the foil is placed over the ramekins. Repeat with another piece of foil. Add the sugar, rice and jasmine tea to the foil lined poacher. Cover and heat over medium heat until the rice mixture begins to smoke. Place the salmon on top of poaching rack, lower into the poacher, turn the heat to low, and smoke the salmon, covered, for 10 minutes. Turn off the heat and smoke the salmon for and additional 10 minutes. The salmon will be cooked medium-rare to medium. Keep the salmon warm in the poacher.
Line a large Chinese-style platter with the thinly sliced cucumbers. Place the side of smoked salmon on top of the cucumbers. Arrange the toast points around the salmon. Present the remoulade in a small bowl accompanying the platter. If desired, drizzle a small amount of the remoulade on the salmon.