Aranjuez is famous for its strawberries and asparagus, both grown in the rich alluvial soil along the Tagus. The strawberry season runs from April to June; asparagus from March to May. Virtually every restaurant in town will put them on the menu in season, and the quality is noticeably better than what you'll find in Madrid. The town has a good selection of traditional Castilian restaurants, concentrated around the central square and the streets near the palace.
A typical lunch in Aranjuez runs to roasted lamb or suckling pig — the hearty Castilian classics — followed by strawberries with cream or a strawberry tart. Prices are reasonable by Spanish standards, though tourist-facing restaurants near the palace entrance can charge more than the value justifies.