Grab a zip lock freezer bag, I find these are best for marinating. If you don't have one use a bowl and cover it with cling film at the end. 

Chop the Chicken into rough chunks about 3cm x 3cm. Place in the bag / bowl and squeeze in the juice of the lemons while you mix the next bits together.

Mix the rest of the ingredients in a bowl until full combined. 

Add some red food colouring if you like the idea if looking like it does in most curry houses. 

Now pour the marinade into the bag and use your hands to squish it around all the chicken it's all covered. 

Squeeze the air out of the bag, up from the bottom to the top, then seal. 

Place in the fridge for up to 2 days 

Get your BBQ nice and hot - lets the coals go white before you think about putting the meat on.

While it's eating up remove your chicken from the fridge and grab 4 or 5 skewers. 

Poke the skewers through the chicken until they're fully loaded. Try and leave a gap between each piece so the chicken chars / cooks evenly around. 

Give your BBQ grill a spray with some olive oil spray to avoid sticking, then place them on top. 

Keep turning throughout cooking (use gloves or a tea towel to turn because they'll get hot)

You want them to start blackening around the edges, but not totally. 

I usually cook for about 7 mins each side. Use a meat thermoter if you've got one and check for an internal temp of 165 F. 

When done remove from the BBQ and place in a dish to cool. 

You can either eat straight away - it's hard not to have some of them, or once cooled place in the fridge to add to a curry later.