Make the Marinade:

1. Finely chop the cilantro, ginger, shallot, and garlic in a food processor. Add the piri piri sauce, olive oil, lemon juice, salt and pepper.  Process about 30 seconds to blend.
2. If you have not had a butcher spatchcock (remove the backbone) your chicken, Martha Stewart gives a nice tutorial. Lay the spatchcocked chicken on your board, skin-side up and press down firmly, over the breastbone, to flatten the chicken.
3. In a baking dish that will hold the chicken (11×7), pour half of the prepared marinade. Place the chicken, skin-side down in the marinade, then pour the other half of the marinade over the chicken. Cover and refrigerate 4-24 hours, turning chicken occasionally.

Make the Glaze:

1. Over medium heat, melt the butter in a small saucepan. Add cilantro and garlic, cook about 2 minutes, garlic will just barely begin to brown.  Add the piri piri sauce and lemon juice.  Reduce heat to Medium-Low; simmer a few minutes until it begins to thicken a bit. If making a day in advance, store the glaze covered in a small bowl, and reheat a bit just prior to glazing grilled chicken.

Grill the Chicken:

1. When ready to grill, prepare your grill to cook using Indirect Heat.  This means heating your charcoal or gas burner on one side of the grill and cooking on the non-heated side.  If you have a 2-burner grill, just heat one burner, or if you have 3 burners, heat the two outside burners leaving the middle unheated for cooking.  I heat my grill to Medium-High when using indirect heat.  Place a disposable aluminum pan below the grill rack on the unheated area to catch marinade and drips.  Then place the grill rack over the drip pan.
2. Brush the grill (unheated area) with oil. Place the chicken skin-side up over the drip pan.  Cover grill and cook, turning every 8-10 minutes, until chicken is done (dark meat should register 165F).  This should take 40-45 minutes.
3. Warm the prepared Glaze.  Pour over chicken.  Serve.