Of course you will want to begin with a seasoned cast iron frypan, and you might even want to try this over an open campfire.
Use just the grouse breasts and figure at least two or three per hungry diner. Marinate the breasts for at least half an hour by coating them with Italian salad dressing.
Add a couple turns around the pan with extra-virgin olive oil and a pat of butter to keep the oil from burning. Sprinkle just a pinch of garlic salt around the pan - Do not go overborad. You can use slices of fresh garlic cloves if you have them.
Cook the breasts for about two minutes over a medium fire (coals) then add slices (not diced) of green & red peppers and yellow onion. Dust with a bit of fresh ground salt and pepper and turn the breasts over. The breasts are done when the veggies are just beginning to wilt. Test one breast to be sure it is white (not pink) all through the meat and serve hot.
White wine or a jigger of Captain Morgan over crushed ice goes well with this dish as do pan-roasted potatoes.