Heat oil in a skillet over medium-high heat.
Add onion chunks, garlic and ginger; cook for 2 minutes.
Add tomatoes and cook for approximately 5 minutes until they become paste-like.
Add garam masala, coriander powder, cardamom and turmeric; stir well.
Add mixed vegetables and cook on low heat until vegetables are soft and tender.
Add coconut milk and mix well.
Simmer for 1 minute.
Add cilantro, cover and turn off the heat.
Season with salt to taste before serving.