Soak wooden skewers in water for 30 minutes before assembling the satays. (If you're using metal skewers, there's no need to soak.)
MAKE THE MARINADE
In a mortar and pestle, add the brown sugar, garlic, minced lemon, jalapeño, coriander, turmeric and pepper.
Pound and mash the combination to a fragrant paste. (If you don't have a mortar and pestle, place the sugar, garlic, lemon, jalapeño, coriander, turmeric and pepper on a cutting board.
Use the flat side of a chefs knife or santoku to rub and mash the combination into a paste -- the sugar acts an abrasive and the constant rubbing, will break down the ingredients.)
Transfer the ingredients to a medium bowl and add the coconut milk, fish sauce, and lime juice. Set aside.
FOR THE CHICKEN SATAY SKEWERS:
Pat the chicken dry with paper towels. Each tender has a thick tendon that should be removed. Place the tender on a cutting board, tendon side down. Hold the tendon between your fingers and run a sharp paring knife along the tendon, keeping the blade parallel to the cutting board. Remove the tendon and discard.
Thread the chicken onto the wooden skewers, weaving back and forth so that the chicken is at one end of the skewer (leaving the opposite end open for turning the kebabs).
Pour the marinade over the chicken (not the skewers) and refrigerate for 20 minutes to an hour.
MAKE THE PEANUT DIPPING SAUCE:
Heat the oil in a small saucepan over medium high heat. Add the garlic, chiles, ginger and shallots and cook for 3-5 minutes, until golden brown. Reduce the heat and continue to cook until the garlic and shallots are caramelized, but not burnt, another 2-3 minutes.
Add the peanut butter and cook, stirring for one minute. Add the remaining ingredients, reduce heat to medium low and simmer for 3-5 minutes, until the sauce is fragrant. If the sauce is too thick (it should be pourable), add water by the tablespoon until it thins out a bit.Taste for seasoning -- adding additional fish sauce, lime juice and brown sugar as necessary. Transfer to a storage container and refrigerate.Sauce gets better after a few days so you can make this ahead of time.
FOR THE RELISH:
Place the sugar, garlic, salt and pepper in a mound on a cutting board. With the side of a chefs knife or santoku, mash the garlic into a paste, using the salt, sugar and pepper as the abrasive. Transfer to a small bowl and add the vinegar. Stir until the sugar and salt dissolve. Set aside.
Combine the cucumber, onion and avocado in a bowl, add the dressing and cilantro. Toss to coat. To make ahead - combine the cucumber and onion and refrigerate. At the last minute add the avocado, dressing and cilantro.
GRILL THE CHICKEN SATAYS:
Preheat your grill to a medium high heat, about 450°. Lay a piece of aluminum foil on one side of the grill. Place the chicken sates on the grill grates so that the "handles" rest over the aluminum foil -- this will prevent the skewers from burning and make it easier to flip.Cook the chicken for 1 ½- 2 minutes on each side or until done. Transfer to a serving platter.
Serve the chicken with cucumber avocado relish, a dollop of peanut sauce and extra lime wedges and cilantro.