Heat oil in a heavy saucepot over medium-high heat. Add onion, garlic and ginger and cook until onion is soft and golden, 5 to 8 minutes. Stir in turmeric, garam masala, chili powder, salt, bay leaf, cinnamon stick and cardamom pods; cook until fragrant, about 2 minutes. Add rice and stir to coat. Cover with tomatoes and vegetable stock and bring to a boil. Reduce heat to a simmer, cover and cook until rice is tender and liquid is absorbed, about 20 minutes. Remove from the heat and let stand, covered, for 5 minutes. Remove bay leaf, cinnamon stick and cardamom pods, then fluff rice gently with a fork and fold in cilantro before serving.