Using poultry scissors, cut backbone from hens, then cut, separating breasts, halving hens.
Place in a glass 13-by-9-inch baking dish.
In a blender combine all other ingredients and process until well blended.
Pour over hens, turning hens to coat well.
Cover with plastic wrap and refrigerate for 48 hours.
Spray grill with vegetable cooking spray.
Preheat to high.
Once preheated, turn gas to medium-high and place hens, skin-side-down on grill.
Close cover and grill 8 to 10 minutes, turn and grill another 8 to 10 minutes, basting occasionally.
Basic Herb Blend:Place all ingredients in blender container and process until ground fine and well mixed.
Store in a zip-lock bag or airtight container.