I'd suggest going to an Allergist and discussing this with them. They can offer allergy testing for common food allergies.
I don't know of any cross-reactivity between penicillin and foods, so if penicillin is the only thing you've reacted to, I'd think you're ok to eat whatever your usual diet is without issues. But be sure to discuss this with an Allergist too.
Chronic Lyme, Bart., Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut dysmotility & non-specific inflammation, Lupus, Osteoporosis, etc.; G-Tube; TPN-dependent
Meds: Flagyl, Essential Oils, Homeopathy, Herbs, etc.