Heat oil in a saucepan and saute chopped onion until soft. Then add ginger & garlic paste, red chili powder, turmeric powder, cumin powder, and fry on low flame for 3 or 4 minutes or till the raw smell disappears. Now add carrot, capsicum, salt, black pepper powder, and lemon juice. Cook on medium heat till vegetables are just cooked. Turn off the heat and make sure that the vegetable mixture is dry. Set aside to cool.