Chicken Yoghurt Recipe and Yoghurt Question

Makes 2 servings in 45 minutes

What I like about Indian cooking is that they use a lot of yoghurt.

I usually put the yoghurt in at the beginning of the recipe,
but then the creamy consistency gets lost in the cooking process.

Is this because i add "the wrong type" of yoghurt,
or is it like that?

INGREDIENTS

-1/2 chicken, cut into pieces
-1 little pot yogurt (5 fluid ounce) (150ml)
-4 cardemons
-3 green chillies (remove seeds) - finely chopped
-1 tbsp coriander leaves - finely chopped
-oil to fry
-salt to taste

-Grind to a paste :
===================
+3 green chillies (remove seeds)
+1 inch (2.5 cm) piece ginger
+6 cloves garlic


PREPARATION

1. Heat oil, add chopped chillies and cardemons and fry for 2 minutes.
2. Add ground paste and fry for another 2 minutes.
3. Add chicken and fry till golden.
4. Reduce heat. Add yogurt, stir well and simmer on low heat till
yogurt is completely absorbed. (30 minutes)
5. Add coriander leaves, remove from heat and serve hot.