In a cooking pan let the oil heat on medium heat.
After the oil is hot, add the mustard seeds into the oil and let it pop until the raw smell of mustard is gone. This will take about 30 seconds.
Next, add cumin seeds, turmeric powder, and curry leaves into the oil. Stir it together.
Immediately add the green beans and 1/4 cup of water in the pan. Cover with the lid and let it steam for 4 to 5 minutes. Stir the mixture in between to make sure the beans do not burn. Add an extra 1/4 cup of water if needed.
After the green beans are steamed, add cayenne pepper and salt as per your taste, stir it together and cover the pan with the lid. Let it cook for 2 to 3 minutes or until the beans are tender.
When the beans are cooked add the Garam Masala, sugar, coconut and lime juice to the beans. Stir the beans and turn off the heat.
Garnish the masala beans with freshly chopped cilantro and serve.