Heat oven to 425 deg F. Prepare a sheet pan with parchment paper.
In a large pot of boiling water, blanch the garlic mustard green for 1 minute. Shock the greens in ice water to stop the cooking process, and squeeze as much water from them as possible
Add the cooked greens to a food processor. Add the nutmeg, salt, smoked paprika, granulated garlic, black pepper, and egg yolks. Pulse until the garlic mustard greens are finely chopped
In a mixer, whip the egg whites until stiff peaks form. With a spatula, fold 1/3 of the egg whites into the greens mixture, mixing until no more whites are seen. Then gently fold in the remaining egg whites, until the mixture is uniform.
Spread the garlic mustard and egg mixture evenly on the parchment paper covered sheet pan, leaving an inch of exposed paper around the entire edge. Bake until the egg is set, about 12-15 minutes.
Loosen the roulade from the parchment paper. Sprinkle the top with whatever you are using as a filling, or just cheese.
Starting with the wider side, roll the roulade up like a jelly roll, ending seam side down. Bake an additional 10 minutes to melt the cheese and warm the filling.