Pour oil into a 5- to 6-quart pan over medium heat. Add mustard seed and cumin seed. When seeds sizzle and pop, in about 30 seconds, add chilies and stir just until chilies begin to brown, about 1 minute.
Add peas, bell pepper, and coconut. Stir until peas are hot, 6 to 8 minutes.
Remove pan from heat and stir in bean sprouts. Pour salad mixture into a wide bowl.
Serve salad warm or cool; just before serving, stir in orange juice and add salt to taste.