The best lunch spots in downtown SF without the wait, according to Yelp

Click on the slideshow ahead to see where you can grab lunch in downtown San Francisco without the wait. Click on the slideshow ahead to see where you can grab lunch in downtown San Francisco without the wait. Photo: Gabrielle Lurie, Special To The Chronicle Photo: Gabrielle Lurie, Special To The Chronicle Image 1 of / 20 Caption Close The best lunch spots in downtown SF without the wait, according to Yelp 1 / 20 Back to Gallery

If you work in downtown San Francisco, you already know grabbing lunch is like solving a math problem. What's the best place you can grab chow within walking distance — and where you'll still have enough time to eat before getting back to your desk — all in 30 minutes?

Fortunately for lunch-goers with a time limit, the folks over at Yelp have some ideas to overcome this eternal question. The company gathered the best lunch pickup locations in SoMa and the Financial District, based on the shortest lines.

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To narrow their search, Yelp looked at the restaurants that had orders between 11 a.m. to 3 p.m. and then determined the businesses that had the highest number of pickup orders. But to speed up the process even more, the restaurant-rating site suggests you order ahead to avoid waiting.

The results were a diverse mix of restaurants and cuisines, like Indian restaurant Chaat Corner and Greek restaurant Ayola. Cafes and delis were also among the most popular businesses where you can be sure to grab a sandwich, if you're looking for something more classic.

Take a look at the slideshow above to see the best SoMa and FiDi spots to grab lunch without the wait.