To prepare the filling of the Chicken Samosa, take a pan and put it on medium flame. Add 1 tbsp vegetable oil. Once the oil is hot, add 1 medium onion finely chopped, 1 tsp grated garlic, 1 tbsp grated ginger, ½ tp salt, and stir. Cook until the onions turn to golden brown and become mildly soft. Add the minced chicken with ½ tsp salt, 1/2 tsp ground cumin, 1/4 tsp chilli powder, and 1/2 tsp ground coriander. Mix these all together and cook for a good 10 minutes. Sprinkle some garam masala into the mixture. For added texture, add the frozen peas. Cook for five more minutes. Taste the salt, and if required, add more. Make sure the mince is dry, it should not be a wet consistency at all.