Our red pandas get Mazuri Leaf-Eater biscuits, dog chow, and fresh produce. The produce is 50% fruit (apples, pears, oranges) 50% vegetables (leafy greens, green vegetables, cooked carrot, and cooked sweet potato). Unfortunately bamboo does not grow well in our climate, so they get this as enrichment, but not as a staple food item.
The biscuits are their least favorite item.
We do not feed whole prey items (mice or chicks), though I am fairly certain they would eat this.