Ingredients

6 Oz Chicken Breast (or Tofu/Shrimp)
1 Green onion
3-4 Thin slices Galangal
2-4 Kaffir Lime Leaves
1 Lemongrass Stalk
1.5 Cups Coconut Milk
1.5 CupsChicken stock 
1/2 Cup Mushroom
1/3 Cup Fish Sauce
1/3 Cup Lime Juice
3.5 Tbsp Sugar ( or mix palm sugar and normal sugar )
1/2 Cup Cilantro
1-4 Fresh/Dried Chilies
1-2 Tbsp Chili Oil
 

Preparation

1.Cube Chicken Breast;
Thinly slice: Green onion and Galangal;
Chop Kaffir Lime leaves;
Chop Cilantro leaves and stems/bottoms separately;
Cut Mushrooms however you like.
2. Put Kaffir Lime leaves, Galangal, and  half of the Green Onion in simmering/lightly boiling Chicken Stock for about 6 minutes.
3. Add Cilantro bottoms (leaf and mostly stems), Chicken cubes, Fish Sauce, Sugar.
4. Boil 5-6 minutes; ensure chicken is cooked. 
5. Add Coconut milk, Mushrooms and any other extra veggies. Bring back to medium heat until it is boiling 5-6 minutes.
6. In serving dish prepare Lime, Chili Oil, other half Green Onion, most of Cilantro, and Chilies.
7. Serve into dish and garnish with remaining cilantro.

1-2 Tbsp Chili Oil and more on the table.