Complex sentence: Bird's Custard was first formulated and first cooked by Alfred Bird in 1837 at his Chemist Shop, in Birmingham because his wife was allergic to eggs, the key ingredient used to thicken traditional custard.
Split into simpler sentences: Bird's Custard was first formulated and first cooked by Alfred Bird in 1837 at his chemist shop in Birmingham. He developed the recipe because his wife was allergic to eggs, the key ingredient used to thicken traditional custard.