Heat up oil and 2 tbsp butter in a large flat frying pan. Once butter is melted, add in cumin seeds. Once cumin seeds start to fragrant, Saute sliced onions, minced garlic and chopped serrano peppers on high flame. Saute for couple of minutes.
Add chopped bell pepper to the translucent onions and saute for couple of minutes on high flame.
Add tomatoes to the pan and saute for 3-4 minutes on high flame.
Add boiled potatoes, peas, carrots, string beans. Saute for 3-4 minutes on high flame.
Add all the spices and mix well along with 1 tbsp butter. Mix well.
Add cooked rice and mix it again carefully making sure the rice does not break.
Cook it for 3-5 minutes on high flame mixing couple of times carefully making sure the rice does not break and heats up all the way through.
Turn off the heat, garnish it with chopped cilantro and scallions.
Add lime juice and mix well. It is ready to serve!