Prepare rice according to package directions. Heat oven to 400ºF. Heat a medium skillet over medium heat and toast curry powder about 30 seconds or until fragrant. Add oil and heat for 1 minute; add onions and sauté 1 minute. Stir in lemon juice. Add chicken and rice and heat for 1 more minute. Season with salt and pepper to taste.
Lay puff pastry sheet on a lightly floured board. Roll out each sheet of dough to a 12-inch by 12-inch square and cut into nine, 4 x 4-inch pieces. Combine egg and water and brush edges of dough lightly with egg wash. Place 1 tablespoon chicken-rice mixture on each square and fold over to form a triangle. Press edges to seal. Brush tops with remaining egg wash. Repeat with other puff pastry sheet. Place pastry pockets on a baking sheet and bake 12-15 minutes or until golden brown. Serve warm with chutney sauce.
Tip: Substitute cooked ham, seafood or vegetables for the chicken.