In a glass bowl, combine chicken thighs with 1 cup of the S&F Carne Asada Sauce; toss to coat. Cover with plastic wrap and refrigerate 50 min.
While chicken marinates, use a mortar and pestle or potato masher and bowl to smash together the avocado, lemon juice, garlic and salt until it’s just blended. Don’t over mix. The avocado should be slightly chunky.
Transfer to a bowl. Fold in the chopped tomato and grated onion.
Refrigerate for 45 min.
Preheat grill on medium-high. Brush thighs with reserved S&F Carne Asada Sauce.
Cook about 10 min.,flipping halfway, until a meat thermometer inserted at thickest point registers 165°.
Transfer to a cutting board and rest 3 min. before thinly slicing.
Heat tortillas over warm grill. Top each with 1 sliced thigh, avocado mix, spring mix, cheese and sour cream. Fold in ends, roll and serve immediately.