Cannibal Collector (2010)
Miguel is a man who appreciates great food, food is his passion but to look at, not to eat. To stifle his need for nutrition he resorts to cannibalism. Where the victims come from is never explained, but they are stored in the freezer for freshness.
Miguel talks to himself constantly, often admitting to cannabilism in the middle of the store.
The movie comes with a stereotypical nosy mom, and a crazy neighbor who hunts aliens on one side, a redneck on the other.
There are many long pauses in dialogue, no character development and terrible reactions over problems such as the food can being the wrong color.
This is perfect for riffing!