Put the lamb, garlic, tarragon, thyme, and rosemary in a medium bowl.  Add the olive oil, season with salt and pepper and toss to combine.  Cover and let marinate in the refrigerator for 1-2 hours.  Remove the lamb from the refrigerator.

Remove the rosemary needles from the stems, leaving some needles at the top.  Thread approximately 6 lamb cubes on each skewer.  Prepare a grill and heat a large cast-iron skillet over medium-high heat.  Add 1 tablespoon of olive oil to the skillet.  Working in batches, add the lamb skewers and cook slowly on each side, approximately 8-10 minutes total.

Transfer the skewers to a large plate or platter.  Serve with lemon wedges on the side.