When I am grilling my steaks, I saute mushrooms, onions & garlic right on the grill in my cast iron skillet. Great toppings for the steak & baked potato.
I also make sausage, peppers & onions in my cast iron skillet. I start with ring sausage:
I cook it for about 10 minutes on both sides, turning once. Then I add chicken stock to steam the sausage for about 15 -20 minutes. I add stock as it cooks so as not to burn the sausage. While the sausage is cooking, I am cutting up red, green, yellow, and orange peppers, slicing onions, and peeling garlic. I remove the sausage after the 40 minutes of cooking, and add the vegetables to the skillet. Once they begin to soften, I add the sausage back in and cook until the peppers are done, the onions are cooked through, and the garlic has become a thickener for the sauce.