is there Mexican restaurant in Vietnam?

yes, u can go to Khoi Thom restaurant on 29 Ngo Thoi Nhiem street, dist 3

I'll have to give them a try as well...thanks.

You can Consult link below:
vanchannel.vn/am-thuc/dia-diem/nha-hang-quan-xa/am-thuc-mexico-tai-tp-hcm-va-ha-noi-12810.htm

1. Mexico Lindo restaurant - 149, Tôn Thất Đạm Str, Dist 1   : (08)39153149
2. Cantina Central Restaurant –  51 Tôn Thất Thiệp Str, Dist 1
3. Charner - 2 floor, 98 Nguyễn Huệ, Dist 1, HCM City
4. Three Amigos Restaurant - 76Bis, Nam Kỳ Khởi Nghĩa, Dist 1   : 08 62990575

Good luck !

Actually, what Awayland seems to be looking for is Tex-Mex food, which is a narrow slice of Northern Mexican cuisine adapted to Southwestern U.S. tastes. What most non-Mexicans nowadays take to be 'Mexican" cuisine. The U.S. itself has at least three different styles of "Mexican" cuisine, being Tex-Mex (and tacos in San Antonio differ from the rolled tacos that were popular in El Paso in my time), New Mexican (with Sopaipillas, etc), and (for want of a better term) and Californian.

Down in Mexico itself, tastes change from region to region, reflecting both the tastes of the area indigenous peoples and the region's history.

So, for all you expats with wanderlust in your souls, Mexico can be a worthwhile detour. But I would start out in one of the regional cities of interest (Cuernavaca, Puebla, Oaxaca, Guadalajara, Aguascalientes, etc) and work my way around. Once you finish Asia, of course.