This is one of the ways my mother-in-law cooks rice. She is from Puerto Rico, her father is from Spain. She lives in Los Angeles now, and every time she visits she shares more of her cooking styles with me. When I visit her, we end up eating out! That's because there is a little home-run Puerto Rican restaurant around the corner from her. Their rice tastes like this, too.
In a large saucepan, cook bacon until fat is rendered. Use a bit of olive oil if necessary to crisp up the bacon or salt pork.
Stir in oregano, garlic, salt, pepper, and vinegar, and cook a couple of minutes over medium heat until fragrant. Add in tomatoes and cook until their liquid is released.
Stir in the rice mix until rice is well coated, then stir in the chicken stock or water. Bring to a boil.
Stir well. Reduce heat to a simmer, cover pot, and cook very slowly without lifting lid for 20 minutes. Then, remove lid, stir well, and allow to cook uncovered until rice dries out slightly, stirring occasionally.
Top with sliced green olives, if desired. Another option is to stir in 1 cup peas, or chickpeas, or pigeon peas and heat through.
NOTE: My mother-in-law used to make this with plain rice and real saffron. But the cost of real saffron has skyrocketed, and she is OK with using the rice mix. She sometimes also adds 1 packet of the Goya Sazon Azafran. I usually leave that out because it is mostly MSG.