Maybe Panang doesn't deliver as far as Mt. Washington. I think they go something like a three mile radius from their location.
Is the taco place you're thinking of El Atacor #11? They serve their tacos in tens...Jonathan Gold wrote about it in last week's LA Weekly. I can attest that the potato tacos are indeed excellent. I didn't know they delivered.
El Atacor #11
2622 N. Figueroa Ave.
Los Angeles, CA
Open 7 a.m. to 4 a.m., seven days.
It's our favorite of the Thai places in the neighborhood - far better than Classic Thai across the street. I didn't know they delivered to Mt. Washington. However Sicha Siam does deliver there.
There's also a little Mexican taco place on Fig in the upper 30s ("10 tacos for 10 dolloars) that delivers. Some friends really like it, we thought it just okay. Sorry, can't remember the name - you'll have to do a search through the archives.