Can I eat fermented foods on an ssri antidepressant?

Yes. Fermented foods contain an amine called tyramine which can cause your blood pressure to elevate significantly. However this usually occurs when you take monoamine oxidase inhibitors (anotherclass of antidepressants) and ingest tyramine. If you plan to consume fermented foods on a regular basis it would be wise to monitor your BP and to consult your physician.
Yes. Yes, you can eat fermented foods while on ssri antidepressants. It is MAO inhibitors which may be a problem with such foods, not ssri's so much.
Pharmacology. Not sure. There is some controversial data that suggests that fermented foods should be avoided in combination with ssri use. The main risk is with MAO inhibitors. Ssri may have inhibition over mao-a but not over mao-b leaving enough if this to be able to handle the tyramine found in fermented foods.