We have enough “restaurants” that fry an egg. We can do that ourselves. Running a proper business requires such formalities to not kill your customers. If knowing about your craft is too hard - allergies is a major part of it - then you shouldn’t be in this business.
Restaurants are one of the classic immigrant paths to upward mobility. We don't want to make that too hard.
By all means, get a license, food handler permit, etc. and know and practice good food safety, and buy ingredients from legitimate wholesalers. But at some point you don't have visibility into the supply chain and it's not reasonable to expect Joe's Taco Truck to know which specific farms produced their lettuce.