I've been twice now to the new(ish) Mexican place in Pennichuck Square plaza on 101A. Both times, I've left full and impressed.
The first time, I went for dinner and ordered the carne asada. I hadn't had it before and wasn't sure what to expect, but was more than pleasantly surprised: two huge pieces of steak with beans, guacamole, and pico de gallo on the side, along with a stack of fresh, warm tortillas. There was so much food, I had enough leftovers for a full meal at home the next day! DH had a burrito combo platter and was happy with it. I like their refried beans better than any other I've had; they're more of a puree, and the flavor is incredible.
DH and I both had margaritas, and be forewarned if you're driving: they're strong! And they don't taste like it, so the alcohol really creeps up on you.
We went back for lunch this week and I got a chicken quesadilla with a side order of refried beans; DH got an enchilada plate. With two Cokes and an iced tea, the bill came to $18 before tip. Very, very reasonably priced lunch, and dinner was the same. Service was great both times (slightly better at lunch when they weren't as busy as with our dinner visit). I'm glad that they're getting the business, though, and hope they stick around. It's nice to have another Mexican option in the area.