Make this a two-part outing: pick up roti sai mai near U Thong Road, then choose a proper meal that fits your sightseeing route. The named stops are not presented as one walkable trail.
Roti Sai Mai Abeedeen-Pranom Sangaroon is a takeaway stop at 32/1 Moo 4, U Thong Road. Michelin describes the specialist as more than 70 years old. The order is simple: fine strands of sugar are wrapped in a soft roti. It suits a snack between sights; it does not replace lunch.
Baan Pomphet, at 13/5 U Thong Road beside the river, suits an unhurried lunch or dinner. Its own menu and the retained Michelin listing emphasize Thai dishes, shared plates and river prawns. Choose it for the setting and a longer break, not for a tightly timed rail day trip.
If you want a quick local lunch instead, beef noodles can make more sense than a destination restaurant. The retained record for Nai Liak still lacks a confidently verified address, so this guide does not route you there until that detail is confirmed.
Both named stops are on U Thong Road, but Ayutthaya's ruins and riverside roads are spread around and beyond the historical island. Check the two map locations before setting out and use a bicycle or tuk-tuk only if the distance, heat and road conditions suit you. Confirm current opening hours, queues and reservations with each venue on the day.