A chap round the corner did this. Cooked Pizzas in an old horse box parked up in a theatre car park. Maybe toward the end of lockdown. He then moved into a shop unit on the local high street, built a great big wood fired pizza oven, bought a decent coffee machine and got a license so he can sell nice beers. He then bought/started renting the unit next door… seems to be going from strength to strength.
See Pizza vans by the roadside in France very often, sometimes only open set days.
Festivals can be a big earner.