Slice chicken into 1/4-inch strips. Slightly pound until even and place in a resealable bag. Add shallots, garlic, coconut milk, brown sugar, salt, Sriracha, pepper, coriander, cumin and turmeric; mix well. Marinate in the refrigerator for 4 hours or overnight.
Soak skewers in water while marinating chicken to prevent them from burning.For the chicken: Remove chicken from marinade. Thread the chicken onto the skewers and place on a baking sheet. Bake until cooked through.
For the peanut sauce: Mix all ingredients for sauce in a medium bowl. If too thick add more water 1 tablespoon at a time. (Can be made 1 to 2 days in advance.)
For the salad: Cut cucumber in half. Thinly slice to create ribbons. Toss with onion and cilantro leaves. Drizzle with vinegar and sugar. Set aside.
Serve chicken with cucumber salad with peanut sauce on the side.