Miss - Carne Asada burritos the size of my forearm from our local hole-in-the-wall shop on Governor and Genesee in San Diego. Bacon/Cheddar/Chipotle fries from del Taco. A "double-double" from In-And-Out Burger.... and my 5 Guys Fries.
Only been gone a month, I assume that will all dim over time. Or I'll remember them as better than they actually are. 
LOL... I was just about to say 'FGS, you've only been gone 5 minutes! How can you be missing anything?!'

You might already be aware of this, but there is a Taco Mazama shop up at your end of Byres Road-- their burritos are pretty nice (and large), even if I don't think of them as authentic. You've also got Lupe Pintos, just a bus ride along Great Western Road, across the road from St Mary's Episcopal Cathedral.... that's where you can buy corn tortillas, enchilada sauce, salsas,and various other Mexican food-creating staples. They also have basic bean & cheese burritos in their freezer, and a small deli counter with fresh guacamole (not as good as what you'd make at home, but) and Mexican cheeses and stuff like that.
Hope that helps a bit!
PS- I used to live on Genesee, near UCSD.
