Preheat the oven to 350 F.

Spray an 8 x 8 baking dish with cooking spray and set aside.

Wash, peel and dice the potato. Set aside.

Peel and dice the onion. Set aside.

Shred the cheese until you have one cup, or measure out one cup of preshredded cheese. Half will go in, half will go on top.

Chop the chives or measure out dried chives. Set aside.

Place a large skillet over medium heat. 

Once the skillet is hot, add the raw sausage. Use a wooden spoon or spatula to break up the sausage into small pieces. It should cook for 4 to 5 minutes. Remove cooked sausage to a paper-towel lined plate and set aside to drain and cool. 

Add the diced onion and diced potatoes to the same skillet. Stir and cook until the onions are soft. (The potatoes will finish cooking in the oven.) Cook for an additional 7 minutes, then move the pan off the heat and set aside.

Whisk together the eggs and milk in a medium-size bowl. 

To this mixture, add in ½ of the cheddar cheese, chives, salt, and pepper and stir.

Transfer the cooled sausage, onions, and potatoes into the prepared baking dish. Spread it around so that it is evenly distributed. Pour the egg mixture evenly over the top. Sprinkle the remaining cheese on top.

Bake in the preheated oven for about 30 minutes. Start checking at the 25-minute mark, sooner if you are using a shallow baking dish. Test doneness with butterknife or toothpick. It should be slightly wet.

Remove from oven and allow to cool for two or three minutes before cutting and serving.

Serving suggestion: Add salsa, a fruit cup, or salad of mixed greens to make a complete meal.

For freezing: Allow to cool completely. Cut into servings, plate individually and transfer to freezer unless slices become semi-frozen, about one hour. Move to freezer baggies or airtight containers, removing as much air as possible, and freeze up to one month. Heat from frozen for one minute in the microwave on high, turn, then another minute on high. Let sit in microwave for 30 seconds before eating.