pistachio covered frozen banana bites

First Smitten Kitchen did it.

Then Joy The Baker did it.

What is a person to do?

Join in, of course (no-brainer).

Here I give you the lazy man's pistachio covered frozen treat.

Everything should be this simple.

Pistachio Covered Frozen Banana Bites
2 over ripe bananas, sliced and frozen
2 bars dark chocolate of your choice (I used one Ghirardelli 70% and one Ghiradelli Semi-sweet)
1/2 cup salted and roasted pistachios, chopped

1. Melt chocolate. Dip banana slices into melted chocolate. Sprinkle with chopped nuts. Refreeze.

Note: I had a problem with the chocolate. Once it was nicely melted and about 10 banana sliced were coated it began to solidify. I turned the heat back on but it never melted again. Chemistry, I tell ya. So I mixed in the rest of the pistachios making a kind of crumbly chocolatey nutty mixture. I t will probably go nicely on top of ice cream.

So I pose a question: How do you keep chocolate melted long enough to get all the slices covered? What causes it to harden and never return to that lovely silken smoothness?