Step 2: Prep. food

Picture of prep. food
If you're using bamboo barbecue skewers then start by immersing them in water to make sure they don't burn when they go on the grill.
Depending on the meat you choose and it's thickness you may have to fillet your cut or pound to tenderize and flatten to a thinner cut. To tenderize meat simply sandwich meat between sheets of wax or parchment paper and pound with meat tenderizer until about 6mm (1/4") thick.  For vegetables, cut lengthwise and create 6mm(1/4") thick slices.

Wheel - Meat (or chicken, pork, eggplant, zucchini):
Cut flattened slices into 12mm (1/2") thin strips.
Season as desired.

Filling - Onions (or asparagus, roasted red peppers, pesto):
Peel onion then cut off one end, continue cutting 6mm (1/4") thick slices.
After cutting, separate each slice into individual rings.

Bacon (optional):
oh bacon...you just keep being delicious and amazing.