1. Cook the rice according to package instructions. Once cooked, let it cool completely.
2. Heat a large skillet over medium-high heat, add the oil, beans, and spices. Cook for 3 to 5 minutes, stirring frequently until the beans are coated in spices and well cooked. Remove from heat and let the beans cool completely.
3. Prepare the dressing by mixing all the ingredients in a bowl.
4. To assemble the jars, start by dividing the dressing among four jars. Add the rice, beans, corn, bell pepper, red onion, avocado, and tomatoes. Top with jalapeño slices and add cilantro if desired.
5. When you're ready to devour it, mix it up before enjoying.