The reason why I call this setup an "onion" is because you layer on iron condors in a single expiration over a several week period as price moves about, yielding a set of short put credit spreads and short call credit spreads that you can "mix and match" to lock in profit. For example, you can take off a short put credit spread you put on the first week you started layering on your iron condors along with a short call credit spread that you put on in the third week or vice versa, depending on how price has moved since you started putting on the layers of your "onion."
Here's the first layer:
QQQ March 18th 94/97/109/112 Iron Condor
Probability of Profit: 56%
Max Profit: 1.10 credit/$110 contract
Buying Power Effect: $190/contract
Of course, this doesn't look like all that hot a setup from the start. The probability of profit is sub-60, which wouldn't be my cup of tea if this was a stand-alone setup. However, the notion is to layer on with price movement over time, yielding spreads that, when taken off in combination, yield higher profit potential than just this setup standing alone.