First find the total time Bill spends chopping peppers: 4 peppers * 3 minutes/pepper = <<4*3=12>>12 minutes
Then find the total time Bill spends chopping onions: 2 onions * 4 minutes/onion = <<2*4=8>>8 minutes
Then find the combined time to grate cheese for and cook each omelet: 5+1 minute/omelet = <<5+1=6>>6 minutes
Then multiply the time per omelet by the number of omelets: 5 omelets * 6 minutes/omelet = <<5*6=30>>30 minutes
Then add the cook time to the chopping time to find the total time Bill spends: 30 minutes + 12 minutes + 8 minutes = <<30+12+8=50>>50 minutes
#### 50