Why do you add the ingredients in sequences when stir frying

I always go in this order:

• Garlic/ginger/chili/spring onion whites

This is to infuse the cooking oil with these flavours. Cook for short amount of time ~30secs.

• onions/peppers/carrots/harder veg

These need a little more cooking that the other bits, so I give them a bit longer.

• mushrooms/sugar snaps/soft veg

These need less cooking, so bit less time.

• bean sprouts

I like these to be a bit crunchy so add them right at then end and basically just warm through.

If I'm using bigger veg like broccoli/cauliflower then I do them separately to the other veg. I use a little of the chili/garlic/ginger and fry that for 30 secs, add the broccoli fry for another minute or so just to brown the florets, then add some water, turn down the heat and put on a lid, to steam the broccoli. Once its done I remove to a separate plate the add back in at the end.

It basically depends on how much you like each veg cooked. If you prefer your peppers crunchy, put them in nearer the end.

Really, this is just to even out cooking times for vegetables that don't have a surface area to volume ratio consistent with the other things you're stir-frying. If you were to shred those green beans, as is sometimes done, you could put them in at the same time as raw, julienned carrots, and they would finish at the same time.

If you put them in whole, you'll end up with beans that are burned on the outside and raw on the inside, as there's not enough time for the heat to penetrate to the center of the bean before the outside burns. Or, if you fry at a lower heat, you could get the beans cooked, but would have to add the carrots later (which means a lower temperature, too, since the beans are dragging heat out of your pan) in order to have them not turn to mush.