We've been eating lahb at Uncle Mustache's for 18 years....and I suspect the place was in business a good number of years before we started. The shop is immediately next door to the mosque on SriChomCheun Road. We're such regular customers and creatures of habit that the staff knows what we want....lahb, dohm soht (beef soup), and seuah long hai (sliced grill beef), a coke, and sticky rice. But a week or two ago my wife spotted a dish at a nearby table and inquired. We ordered it. It's a beef soup, served over a charcoal pot in the center of the table, with plenty of large onion, basil, dill, lemon grass, chili pepper, and crushed grilled rice in a hearty beef stock.....oot pyeh (อุเพี้ย). It's a meal all alone.....but we still pigout with lahb and grilled beef.
Uncle Mustache has semi-retired, but his very capable sons have been running the business for a few years.
It's been my go-to-place when we have foreign visitors in town who want an authentic Thai dish.
My wife and I often walk in talking about ice-cream after lunch....but walk out too stuffed to do so.

That's it, kakariki. The restaurant is to the immediate left of the mosque as you're facing the mosque. Closed Sundays. Dishes are 70baht, except ootpieh which is 80. Ootpieh is normally served kohm, so if you don't like it like that, ask for mai kohm . We usually get it mai kohm.
20 years, same family, never a disappointment