Heat oil in a large frying pan over medium-high heat. Add chicken in batches. Cook, stirring for 5 minutes or until golden brown. Transfer to a bowl. Add onion, garlic and mushrooms to pan. Cook, stirring until mushrooms are tender.

Return chicken to the pan. Add Gravox Chicken Gravy. Cook, stirring for 1 minute. Add stock, season with salt and pepper. Reduce heat to low. Simmer, for 10-15 minutes or until sauce thickens. Stir in cream. Remove from heat. Cool.

Pre-heat oven to 200°c. Grease 4 x 7.5cm (base) x 11cm (top) pie tins. Cut short crust pastry in half diagonally to form 4 large triangles. Line base and side of 1 pie tin with 1 piece. Trim edge and brush with egg. Repeat with remaining triangles. Spoon chicken mixture into cases.

Cut puff pastry into 4 squares. Place 1 square over filing. Trim edge. Repeat with remaining puff pastry. Place tins on a baking tray. Brush tops with egg. Sprinkle with sesame seeds. Bake for 30 minutes or until golden and puffed. Serve.