1 bag large marshmallows
I have not listed amounts of ingredients since I have never measured them. For a single loaf pan, you will probably use less than the whole bag of marshmallows. The only ingredient that limits this recipe is the amount of chocolate. I usually buy chocolate in bulk pieces and buy the largest piece I can find. Any specific amount of an ingredient should be determined by your own taste preferences.
If you choose slab chocolate you must chop it for easier, faster melting. I see no reason not to use chips if available. Keep the water level low on the double boiler, as common cooking technique dictates that the top pan not touch the water. I have also read that the water should be simmering rather than boiling.
As you are waiting for the chocolate to melt, cut the marshmallows in half and place them in a buttered loaf pan. I keep scissors in the kitchen and find them to be the best tool for this particular job. Sprinkle on as many chopped nuts as appeals to you.
As soon as the chocolate melts, pour a portion of it over the marshmallows and nuts. What is a portion? Enough to partially cover the pan contents and drip onto the bottom of the loaf pan. Add a second layer of marshmallows and nuts, then cover them completely with the remaining chocolate and scatter more nuts on top.
There will be some gaps which are fine. If they were filled with chocolate the candy would be too dense. After the chocolate solidifies (placing in the refridgerator helps speed the process) take the Rocky Road from the loaf pan and cut it into bite size pieces.