Clean the seeds out of the acorn squash - wrap the acorn squash with foil and place on the on the grate out of your way for now. Pinch the foil on one side when wrapping them to make a guide and a handle for the tongs, this helps when you need to turn the squash.
Cut the bell peppers and onions into rings, season with salt and pepper.
Using either foil or a large roasting pan that fits on your grill, melt butter (amount varies by the quantity of food being cooked - you want at least a thin coating across the bottom of the pan) and add olive oil. Add the peppers and onions, along with a bit of water or beer (no more than a cup) to prevent burning. Cover with aluminum foil to keep the moisture in the pan.
Start browning your sausage on the grill - you don't need to cook the sausage through at this point, just get some of the flavors from the grill on it. If you have some smoking chips, they work great at this stage.
Check the onions and peppers every few minutes to make certain there aren't any hot spots in the pan, adjust the pan and stir as needed.
After 10 minutes, turn the acorn squash to let them cook evenly.
When the peppers and onions have softened, add the sausage to the pan, along with the canned tomatoes. Turn the heat up (or adjust the pan position for maximum heat) and keep the aluminum foil on top as much as possible to keep the moisture in the pan.
In another pan, combine the second can of diced tomatoes and mixed greens, simmer while finishing the sausage.
Check the acorn squash - with an oven mitt (or leather glove) press on the sides, if they are soft, they are ready to eat and can be moved to the warming rack, or pulled off of the grill.
Check the sausage mixture roughly every five minutes. You want the liquid in the pan to be simmering. The sausage should be cooked through in ten minutes or less, depending on the thickness of the sausage and how hot the grill is.
After no more than ten minutes, cut one sausage in half (or use a cooking thermometer) to check - if cooked through, pull off of the grill and enjoy, if not, wait another 4-5 minutes and repeat.