Heat the olive oil in a large Dutch oven over medium heat. Add the onion, poblano pepper, and jalapeno pepper, and cook, stirring often, for 8-10 minutes, or until softened.
Add the diced sweet potatoes, garlic, chili powder, cumin, and cayenne pepper and cook, stirring constantly, for 1 minute. Season with sea salt and freshly cracked pepper, to taste.
Add the chopped tomatoes along with their juices to the Dutch oven and 1 cup of broth and stir, scraping up the browned bits. Add the undrained beans and stir to combine. Bring the chili to a boil.
Once boiling, lower the heat to a simmer and cover with a lid. Simmer for 35-45 minutes, until the sweet potatoes are tender. Simmer for a longer time, for more depth of flavor. The flavor concentrates as it cooks. Add more broth if you need to thin the chili. Taste the chili and season with more sea salt, freshly cracked pepper, or cayenne pepper to taste, if needed.
Ladle into bowls and serve with fresh cilantro, shredded cheese, green onion, and sour cream on the side if desired. Enjoy.