Slice the portabella mushroom caps length wise into 1/3 inch thick slivers, getting about six slivers from each cap. Skewer each of the mushroom slices lengthwise. Brush lightly with 1 Tbsp. of the olive oil. Sprinkle with 1 Tbsp. Mrs. Dash® Garlic & Herb Blend. Preheat a grill or grill plate to medium. Grill on each side about 2 minutes. Place on serving platter. Mix the additional 1 Tbsp. of olive oil with the Mrs. Dash® Garlic & Herb Blend and set in small ramekin to use as additional dipping sauce.