Over medium heat, add oil in a 5-quart pot.
Sauté onion and bell pepper until softened, about 5 minutes.
Add tomatoes and chili powder. Bring to a simmer.
Reduce heat and let cook for about 10 minutes.
Add beans and corn. Add hot pepper sauce (optional).
Let simmer for at least 20 minutes to bring flavors together.
Season with salt and pepper.
If chili becomes too thick, add water 1/2 cup at a time to create desired consistency.
Top with low-fat cheddar cheese and plain Greek yogurt to taste.
Serve and enjoy!