Dice half the salmon into 1/8-inch cubes; set aside in a medium bowl. Process the other half in a food processor until slightly chunky; add to the diced salmon.
In a separate bowl, combine the cilantro, green onion, soy sauce, sesame oil, smoked paprika, garlic and lime juice. Add the cilantro mixture to the salmon and stir gently until just combined. Season with salt and pepper. Shape the salmon mixture into 4 patties and chill, covered, in the refrigerator for 15 minutes.
Heat a grill to medium-high heat or heat a nonstick skillet with the grapeseed oil over medium-high heat. Cook the salmon patties until browned on the first side, 3 to 4 minutes; flip and cook until browned on the second side, about 3 minutes more. Place on the buns and top each with a dollop of Rhubarb Chutney. Garnish with some lettuce, red onion and pickles, as desired.
Combine the rhubarb, cherries, brown sugar, blueberries, cherry juice, red pepper flakes, red onion, ginger and garlic in a large saucepan. Bring the mixture to a boil, reduce the heat to medium-low and simmer, stirring occasionally, until the onions are translucent, about 20 minutes. Stir in the honey and vinegar and continue to cook over medium-low heat until it coats the back of a spoon, about 15 minutes more. Cool and store in the refrigerator for up to 2 weeks.