When the sausage slices are browned, remove them from the pan with a slotted spoon, place in a bowl and cover with aluminum foil or a plate to keep them warm.
Add the diced potatoes and onions to the pan, cook over medium-low heat, stirring occasionally until the onions are browned and the potatoes are tender. (10-12 minutes)
Add the diced red pepper to the pan, along with the Italian seasoning and the salt and pepper, cook for 2-3 minutes
Remove the vegetables from the pan with a slotted spoon, placing them in the covered bowl with the sausage.
Drizzle a little more olive oil in the pan, if needed.
Add the chopped spinach to the pan with the mushrooms, cook until the spinach is well-wilted. (1-2 minutes)
Add sausage and vegetable mixture from the bowl back into the pan, add the red pepper flakes then toss together for 1 minute to reheat the sausage and vegetables before serving.
Recipe by Campsite Bistro at https://campsitebistro.com/smoked-turkey-sausage-skillet-with-red-pepper-spinach/