A robot will like to eat robot things and human food will not be too delicious for it.

1. A delicious mildly rusted (for flavor) nut. Yummy enough to restore 10% of the health after one bite! An important component of a complete breakfast.
2. A battery charged to exactly half like all things absolutely should not be, but where are you going to get a refund in a post-apocalyptic wasteland robot city? Still nice and juicy to restore 50% of health after one lick!
3. An oil can. Nothing quite makes an old robot feel young again like proper joint lubrication. Dance again like it's 2086 and you can fit into your old chassis!
4. A disgusting chocolate bar. Who would eat something like this? Absolutely vile. Gross. Get it away from me. My hydraulic pressure is already high, I don't need any more stress-testing in my life. NO DON'T GIVE IT TO THE DOG!

Palette used - https://lospec.com/palette-list/patina