Keeping Your Opponent Helpless
Seirawan Strategy Example #2
Winning Chess Strategies, Diagram 14, p39
Seirawan reveals the theme of this example of play is "better safe than sorry." ... Basically, White has the Material Advantage and shouldn't bother trying anything exotic to win -- he just has to play it safe by escorting one of the Pawns to gain Promotion, get a Queen back on the board, and then make mincemeat of Black's King.
White should avoid showboating; he just needs to ensure that his King doesn't get into trouble from Black's Rook, which Seirawan points out is still "a strong piece", and then trap and Mate Black's King against one of the edges of the board (to see how, take a look at the Shepherding Strategy).
Seirawan shows the easiest way to deal with Black's Rook, in this position, is to trade Rooks, by taking advantage of an Absolute Rook Fork (Tactic) -- Black will be forced to capture with the Rook, enabling White's g3-Pawn to complete the trade, and White will have an easy time Promoting a Pawn or two and Checkmating Black's King (unless Black were to Resign; but then this is a hypothetical position, so let's not get carried away).