My favorite tortas place in SF is Boss Voni at Mission & Geneva.
This place opened in 1999 with the name "Bugs Bunny". Apparently they were ignorant of the sort of trademark infringement lawsuits that conglomerates like Warner Bros. can slam on humble hash houses.
Time Warner must have disabused them, because they suddenly changed their name to "Boos Voni," an amusing Spanglish phonetic rendering of the famous cartoon character's name, one that eluded the wrath of AOL et al.
Now they've semi-anglicized their name to "Boss Voni," a name that conveyes the superiority of their bill of fare to English speakers. Their logo, which once sported the familiar "Merrie Melodies" concentric circles, now depicts a big yummy torta.
Try the torta de milanesa, a huge _pan_ sliced and smeared with refried beans, then stuffed with breaded steak, tomato, avocado, and pickled jalapeno, among other tasty ingredients. I can only eat half. I take the other half to go.
Then I head south on Geneva to the Lucky Wealth Chinese Restaurant, the best source for bubble tea outside of the Avenues.
And don't forget to pick up a bag of imported Mexican candy at the dulceria at the corner on your way to Lucky Wealth. You can't miss the dulceria; there are pinatas on display outside the establishment. I recommend a bag of Pico. These little packets of sugar, salt, and chile powder can be sprinkled on the tongue and savored. They also make great seasoning for apple or jicama wedges.