In a large skillet over medium-high heat, cook and stir the ground beef until browned and crumbly, about 5 to 7 minutes. Drain excess grease.
Add the green pepper and onion to the skillet; cook and stir until the onion is soft and translucent, around 5 minutes.
Mix in the diced tomatoes, tomato sauce, chicken broth, thyme, and sage. Season with salt and pepper. Cover and simmer until the peppers are tender, for about 30 to 45 minutes.
In a separate saucepan, bring water and rice to a boil. Reduce heat to medium-low, cover, and simmer until the rice is tender and the water is absorbed, approximately 20 to 25 minutes.
Stir the cooked rice into the soup, heat through, and serve.
Notes
For a heartier version, consider adding cooked beans or corn to the soup.