Heat 2 tbsp oil in a pan. Add 1 tsp cumin seeds, a few chopped curry leaves, 2 chopped green chilies, and 1 cup chopped onions. Sauté until the onions turn soft and light golden.
Lower the flame. Add 1 tbsp Kashmiri red chilli powder, 1 tsp coriander powder, ¼ tsp turmeric powder, and 2 tbsp water. Mix well and sauté the spices until aromatic.
Add 500 grams (4 medium-sized) boiled potatoes, 1 cup (100 grams) green peas, salt to taste, 1 tbsp garam masala, 2 tbsp sugar, 1 tsp lemon juice, and a handful of chopped coriander leaves. Mix everything well.
Mash the potatoes and green peas using a potato masher until the mixture is smooth and well combined.
Once everything is evenly mixed, switch off the heat.
The aloo masala is ready. Keep it aside.