You put the bread down, two pieces stacked exactly as they were in the loaf. You open them up like a book, so they are geometrically similar on the surfaces to be covered. First spread the jelly, or jam, edge to edge, all the way across, thick enough to completely cover the bread. Wipe the spoon gently on the inner face of the other piece. Then spread the peanut butter, evenly, not quite to the edge, with several “S” curved swirls, along the face of the bread. Don’t wipe the knife on the outside of the sandwich, or everyone will know that you were poorly raised, and think ill of your mother. When no peanut butter is desired, the second piece of bread is optional, and the resulting preparation is referred to as a jelly bread, whether or not the second piece of bread is included.
Some matters are simply too important to be left to chance. When you open the new jar of peanut butter, or of jam, you write peanut butter, or jam on the shopping list immediately. Better safe, than sorry.