Heat the oil over medium-high heat in a soup pot. Add the onions and sauté until translucent, 2 to 3 minutes. Add the garlic and sauté for 1 minute. Add the stock, sweet potatoes, russet, and salt. Cover and simmer until the potatoes are tender, about 15 minutes. purée the mixture in batches, then put the soup back over low heat and add 5 tablespoons of the honey, the bell pepper, curry powder, pepper, and ginger. Bring to a simmer, taste and adjust seasonings. Microwave the remaining 1 tablespoon honey for 5 seconds on High. Serve the soup drizzled with a little warm honey and sprinkle with chopped cilantro, if desired.