First, we need to determine the total amount of minutes available for cooking. We do this by performing 2*60=<<2*60=120>>120, as there are 60 minutes in an hour.
Now that we know we have 120 minutes, we then divide the preparation time into the total amount of time by performing 120/20= <<120/20=6>>6 dishes capable of being made.
Since each dish can feed 5 people, we find the total number of people fed by performing 5*6=<<5*6=30>>30 people.
#### 30