Tortilleria Santa Cruz in Escondido
I saw this place as I was coming down Valley Parkway (it's on cross street Rose Ave.), and stuck my head in to see what was going on. I left with two big chicken tacos with lots of meat and a great cooked red chile salsa. The taqueria is a nice little market, very small, and appears to be attached to the commercial tortilleria next door. I'm not sure if they make their own nixtamal like at Los Reyes and Franciscos in Vista, but the tacos were succulent and flavorful. I think I spied bags of instant masa being loaded as I drove up.
They also had birria de res and carnitas and buche, none of which I tried. There's also a bakery case: I think they might have started out as a panaderia, since the sign over the tortilleria entrance is 'panaderia' turned backwards so it can't be easily read.