Preheat the oven to 425 degrees. Meanwhile, cut the carrots and peppers into chunks and the onion into half inch thick slices.
Toss the carrots in a little bit of olive oil, salt and pepper, and place in a roasting pan in the oven.
Toss the cherry tomatoes, bell peppers, and white onion with more olive oil, salt, pepper and the garam masala and curry powder. After the carrots have roasted for 8 minutes add the rest of the vegetables to the roasting pan and roast for another 25, or until the edges start to blacken.
Remove the roasted vegetables from the oven and place in a stockpot, making sure to scrape out all the juices and spices. Add the stock and peeled ginger and bring to a boil. Reduce to a simmer and let cook for 30 minutes, making sure all the vegetables are completely cooked through.
Remove the ginger and either working in batches in a blender or better yet an immersion blender puree the soup until smooth.
Mix the cardamom with the yogurt and serve the soup with the yogurt, cilantro and pumpkin seeds on top.