Fine Print Sergio's Mexican Grill 281-256-7077. Equal or Lesser Value. Excluding Alcohol & Tax. Valid Monday Through Thursday All Day. Saturday and Sunday after 3pm. Value up to $5 for Lunch, $7 Dinner. Dine in Only. Coupons may not be combined with any other offer. With Valpak® coupon only. Must present coupon at time of purchase. Coupon void if altered.