Melt the clarified butter in the pan then spread the potato slices out in the pan and let them cook until browned on one side, about 8 minutes.
Flip them over, add the speck and the fried onion rings back into to the pan, Sprinkle the fresh chopped sage over the potatoes and cook for another 5 minutes.
Season with Kosher salt and freshly ground black pepper to taste.
Remove from heat, transfer to a serving platter, garnish with fresh sage leaves and serve.