I can't imagine I didn't find this place for this long. Thank you yelpers for the recommendation.
The restaurant is tucked nicely inside of the grocery store. It's real deceiving how small it looks from outside. It's a huge space inside. Very authentic charm to it. The menu was big, colorful and staff was very attentive. Even with some rush, we were served right away.
We tried taco, gorditas, sopas and quesadillas. Everything we ate was excellent. I wanted tongue tacos but they ran out of it at 3pm... so I ordered steak instead. I am reluctant to give 5 stars just because their salsa wasn't as great as I have had at other Mexican restaurants in Madison. The chips wasn't made to order fresh as well.
We would sure go again to this place. Anyone who likes a good authentic Mexican cuisine, must give this place a chance. There's plenty of space for huge groups as well.