Take a baking dish or, if you prefer, a round mold, and grease it well with olive oil.
Line the bottoms and sides with scripelle. The one that line the sides hang over the sides by half.
Moisten the scripelle at the bottom with a thin layer of the bagnata.
Spoon a layer of the sauce with its tiny meatballs (and, if using, peas) then dot with mozzarella and sprinkle with the grated cheeses.
Lay down another layer of scripelle, this time covering just the sauce and other filling ingredients, not the sides. Moisten with a few spoonfuls of the bagnata, then spoon over another layer of the sauce and the other ingredients.
Repeat until you've used up the filling ingredients. (You should have at least four layers total.)
Fold the scripelle that are hanging over the sides of the dish or mold towards the middle. If the filling ingredients are still showing, lay over one or more scripelle to cover the gap. Moisten once again with the bagnata.