What are the foods are eaten on ascension day?

Mon, Tues, Wed before Ascension are traditional semi fasting days with no meat, called "grass days"(vegetarian).

If Greek or Armenian then Dolmen, stuffed grape leaves are eaten. Ascension Day is often mixed with Spring First Fruits, you see, and young grape leaves come with Spring.

I would think a spring vegetable soup would be appropriate, as well as something like a baby spinach salad or baby carrots, if you go that route. Fresh baked bread is common.

Going Fishing and eating the fish is done by some. Many countries have holidays with hikes or go for a picnic or see a religious parade.

Center pieces in Portugal are a bouquet with new wheat, olive branches, and young grape leaves.

But protestants eat anything and just go to a service, if they have one.