Fish/seafood makes sense for a coastal location. Anywhere crop cultivation is possible, there will nearly always be something based on the local grains, plus if they have enough abundance of any other produce so that it's cheap, that'll show up too. I'd bet on grilled/charbroiled and fried-in-oil as common on-the-spot preparations, served on a stick or straight into the customer's hands, shirttail, apron, etc.
Shortly before the time of Scappi, in the late 1400s, Bartolomeo Sacchi called Platina had published De Honesta Voluptate et Valetudinae, "On right pleasure and good health," which is sadly not available online, but there's an excellent translation in print by Mary Ella Milham, Pegasus Press, 1999, which gives some commentary and context beyond the translation. Recipes I recall include a salad of mixed wild and cultivated herbs, including fennel, dressed with oil and vinegar; a squash soup (using vegetable marrow, which we don't tend to see in the US, but it's sort of like the bastard child of a zucchini and a winter squash) flavored with wine and parmesan and almond milk and spices; a squash pie (again with the vegetable marrow, I guess they had a lot of them) along vaguely the same lines as a modern pumpkin pie: cooked squash flesh mixed with spiced custard, baked in a pie shell; a vaguely quiche-like pie of herbs/greens cooked with soft cheese, beaten eggs, and sweet spice in a pie shell; various fritters and omelets, various preparations of meats, poultry, and seafood that I don't recall. I think all but the soup would make plausible street food.
Around the same time, an anonymous Venetian cookbook was published, with some overlap in recipes with Platina. There's a decent hobbyist translation online: http://helewyse.medievalcookery.com/libro.html
Re: street food
Anywhere crop cultivation is possible, there will nearly always be something based on the local grains, plus if they have enough abundance of any other produce so that it's cheap, that'll show up too. I'd bet on grilled/charbroiled and fried-in-oil as common on-the-spot preparations, served on a stick or straight into the customer's hands, shirttail, apron, etc.
Shortly before the time of Scappi, in the late 1400s, Bartolomeo Sacchi called Platina had published De Honesta Voluptate et Valetudinae, "On right pleasure and good health," which is sadly not available online, but there's an excellent translation in print by Mary Ella Milham, Pegasus Press, 1999, which gives some commentary and context beyond the translation. Recipes I recall include a salad of mixed wild and cultivated herbs, including fennel, dressed with oil and vinegar; a squash soup (using vegetable marrow, which we don't tend to see in the US, but it's sort of like the bastard child of a zucchini and a winter squash) flavored with wine and parmesan and almond milk and spices; a squash pie (again with the vegetable marrow, I guess they had a lot of them) along vaguely the same lines as a modern pumpkin pie: cooked squash flesh mixed with spiced custard, baked in a pie shell; a vaguely quiche-like pie of herbs/greens cooked with soft cheese, beaten eggs, and sweet spice in a pie shell; various fritters and omelets, various preparations of meats, poultry, and seafood that I don't recall.
I think all but the soup would make plausible street food.
Around the same time, an anonymous Venetian cookbook was published, with some overlap in recipes with Platina. There's a decent hobbyist translation online: http://helewyse.medievalcookery.com/libro.html