Heat large skillet (a 12-inch cast iron is recommended) over direct medium heat (350°-450°F) on grill. Add sausage and cook 4-6 minutes until cooked through, breaking up any chunks. Transfer sausage to a plate.
Heat oil in same skillet. Add potatoes and 1 ½ teaspoon seasoning. Close hood and cook potatoes 15 minutes or until lightly browned, stirring occasionally. Add sausage back to the skillet and stir well.
Whisk eggs, milk and 1 ½ teaspoon seasoning together in a medium mixing bowl.
Form a well in potato/sausage mixture and add eggs. Stir to combine. Close hood and cook for 5-7 minutes.
Stir in half of the cheese and tomatoes. Sprinkle remaining cheese on top of the potatoes. Top with onions. Let cook 1-2 minutes so that cheese is mostly melted.
Pack your skillet full of flavor with Weber® Roasted Garlic & Herb Seasoning.