Bring the water to a boil in a saucepan with a lid, sprinkle in the rice, stir in the salt, and cover. Reduce heat and simmer until the rice is tender and the liquid has been absorbed, 20 to 25 minutes.

Place the ground beef in a skillet with a lid, sprinkle with salt and pepper, and brown over medium heat, breaking it up as it cooks, until the meat is crumbly and no longer pink inside, about 10 minutes. Remove the beef and skim off most of the fat from the skillet, leaving about 2 teaspoons. Stir the onion and bell pepper into the skillet with the reserved drippings, and cook and stir until the onion is translucent, about 5 minutes.

Scoop the cooked rice into the skillet, stir to break up the rice, and pour in the tomatoes and cooked ground beef. Stir everything together, cover, and cook over low heat until the flavors have blended and the dish is hot, about 10 minutes.