San Bruno punches above its weight for food, mostly thanks to the Filipino, Chinese, and Mexican immigrant communities that have settled here. A walk along San Mateo Avenue, the closest thing the city has to a main street, turns up half a dozen good options.
Hangry Planet on San Mateo Avenue claims to be the first vegan convenience store in North America, with cold-case sandwiches, plant-based pantry staples, and a small café area. Marination further down the same street does Hawaiian–Korean fusion — the kalua pork tacos and Spam musubi are the things to order. For sit-down dim sum, Koi Palace in nearby Daly City is widely rated as one of the best Cantonese restaurants in Northern California; it is fifteen minutes' drive north.
The El Camino Real strip is lined with Mexican taquerías, Filipino bakeries (try the ensaymada at Valerio's), and Vietnamese phở counters; for an authentic lechon dinner the long-standing Filipino Heritage Cuisine is worth seeking out. None of this is fancy, but most of it is the real thing.