In a large skillet or dutch oven, warm the olive oil in a pan and saute the sliced onion until it becomes transparent.
Then add the garlic halves and saute them until fragrant.
Add the tomatoes and saute for another minute or two.
Pour the green beans in, add 2 cups of water, the tomato paste, the red pepper paste, bell pepper (if using), salt, black pepper, and Aleppo pepper.
Bring to a boil and simmer while the green beans cook. Add more water, as needed. It should be stewy, not soupy, once the green beans are tender.
Taste and adjust seasonings, as needed.