Hi Ian,
Thanks for posting you're recipe, alas I have never got on with Tikka marinated in yogurt, I don't know what it is but it just doesn't gell with me... but as everyone says, each to their own and if they enjoy it this way then that is fine

I have always used Blade's recipe, but with a few slight changes as below. I have tried all sorts of Tikka recipes here but this is my favourite.
Ingredients
600g Chicken - 4 or 5 breasts
1 heaped tablespoon Pataks tikka curry paste. (Not tikka masala paste).
1 heaped tsp garlic paste
1 tsp ginger paste
2 tablespoons lemon juice (Jiff is ok)
1/2 tsp chilli powder
1 desert spoon spice mixture (10ml) see below.
1/4 tsp Orange food colouring (If powder just a sprinkle)
1 level tsp methi (Fenugreek leaves)
1 level tsp salt
1 tablespoon veg oil
3 tablespoons of water
(For a hotter Tikka, I very finely slice 2 green chilie?s, well more like shave them really, and add to the marinade along with 1 tsp of Rajah extra hot chili powder and use red food colouring instead of orange for effect).
Bunch fresh coriander (cilantro) chopped
Spice mixture ? this makes enough for the Chicken Tikka and enough to store in a small herb jar for future use. Just mix it all together.
8 parts ground coriander
7 parts turmeric
5 parts ground cumin
4 parts curry powder
4 parts paprika (optional)
I use ? teaspoons for the amounts above and that usually makes approximately 2 tablespoons of spice mix which is normally enough for 2 separate curry dishes.
However if you?re curry dish warrants more then just increase the quantities in the proportions above.
Method
1. Chop the chicken breasts into 2 or 3 pieces each
2. Mix in 2 tablespoons lemon juice to the chopped chicken, leave for 15 mins
3. Meanwhile mix the rest of the ingredients in a bowl
4. Add the runny spice mixture to the chicken, cover and leave in fridge for a minimum of 4 hours. I leave it for 48 hours.
5. Put the chicken pieces onto skewers
6. Heat oven grill to highest temp and leave on full blast for 5mins to ensure it is HOT
7. Place skewers on a dish where both ends of the skewer are supported at both sides of the dish making sure the dish is deep avoid the chicken touching the bottom (i.e. ensure the chicken is suspended)
8. Place dish under grill (I try to get the chicken pieces about 2 inches from the grill element
9. Cook for 2-3 minutes turn once and give them another 2-3 mins
10. Or just fry in a dry pan until done. Turn frequently.
11. Or, stick on BBQ for smokey taste. (This is my preferred method).
I think that cooking on the BBQ gives it the best taste, with that smokey finish...