In a large bowl, mix up the marinade by mixing together the butter, garlic, lemon juice and soy sauce.
Allow the cornish hens to sit in the large bowl of marinade for 1 hour. I flipped them over at 30 minutes.
Once they have marinated, fire up the grill.
Place them flat on the surface of the hot grill. I cooked them for 20 minutes each side. I used a spatula to press them down and keep them flat while they are cooking. I have heard of others putting a foil covered brick on top, we did not do that, I just simply pressed them down a lot. I also added more marinade as they were cooking.
Total cook time was about 40-45 minutes for juicy, delicious Cornish Hens.