In a blender, combine coconut milk, lime juice, lime zest, basil leaves, green onion, cilantro, brown sugar, grated ginger, garlic powder, coconut aminos, rice vinegar, allspice, sesame oil, and minced Thai red peppers. Blend until smooth. In a bowl, toss the chicken cubes with the marinade, ensuring they're well coated. Cover and refrigerate for at least 2 hours, allowing the flavors to infuse—overnight is best for rich taste.

While the chicken marinates, prepare the gremolata. In a small bowl, mix together chopped saffron, crushed roasted cashews, sesame seeds, and lime zest until evenly combined. This vibrant topping will add a refreshing crunch that complements the Thai Spicy Basil Chicken Skewers. Set the gremolata aside until ready to serve, letting the flavors meld beautifully.

In a saucepan over medium heat, melt the plant-based butter. Once melted, whisk in the remaining cashew sauce ingredients: reserved coconut milk, minced Thai red pepper, brown sugar, rice vinegar, grated ginger, garlic powder, salt, black pepper, and sesame oil. Cook for about 5 minutes, stirring continuously until the sauce thickens slightly. Remove from heat and keep warm for serving alongside the skewers.

Preheat your grill to high heat while threading the marinated chicken onto skewers, ensuring an even distribution. Oil the grill grates to prevent sticking, then place the skewers on the grill. Cook for approximately 10-15 minutes, turning occasionally and brushing with reserved marinade. The chicken is done when it reaches an internal temperature of 165°F and is charred and juicy.

Allow the grilled Thai Spicy Basil Chicken Skewers to rest for a few minutes after removing them from the grill. Sprinkle the gremolata generously on top, adding brightness and texture. Serve hot with the creamy cashew sauce on the side for dipping, creating a deliciously cohesive dish perfect for any gathering or leisurely dinner.