The restaurant that you guys went to eat is a vegetarian restaurant (Vegetarian food) (If any store puts up a yellow flag like this at the store. It shows that they sell vegetarian food. )for the Indian people in that area. Some people don't eat meat. Phahurat is a place where Thai people of Indian descent have lived. They have been here for 4-5 generations and are already Thai. But there are still Indian-style residences. There is a Sikh temple. Live there too (Phahurat means little India, like Yaowarat means Chinatown).
Jay stalls are indeed vegetarian, but the specific stall we visited also doesn’t serve egg or dairy products, making it vegan friendly, as well as vegetarian friendly. We did check ourselves, but it’s also been independently verified.