Combine all ingredients for the coconut rice in rice cooker. If cooking on the stovetop, follow directions on package and substitute recommended amount of water for coconut milk.
Sprinkle salt and pepper on both sides of tilapia and set aside.
In a large pan, add oil and when hot add chili pepper and garlic and ginger and cook for 3 minutes using medium-high heat. Add bell pepper, tamarind, lime and fish to the pan (plus fish juice and chilis, if desired) and cook for another 3 minutes.
Make space for your tilapia fillets in the center of the pan, add fish and cook covered for 5 minutes.
Serve tilapia while hot with fresh rice, and top with cashews, cilantro and green onions.