In a large pot or Dutch oven, heat 2 tablespoons of olive oil over medium heat. Add the diced yellow onion and chopped celery, cooking until they soften, about 5 minutes. Stir in the minced garlic and jalapeño (if using), cooking for another minute until fragrant.
Stir in the chopped green and red bell peppers, along with the tomato paste. Cook for an additional 2-3 minutes, allowing the paste to caramelize slightly and deepen in flavor.
Pour in the 30 ounces of diced tomatoes and the 3 cups of low-sodium vegetable broth. Stir to combine all the ingredients well.
Add the dried oregano, basil, thyme, smoked paprika, chili powder, cayenne pepper, kosher salt, and black pepper. Mix thoroughly and bring the mixture to a boil.
Once boiling, add the 3 cups of cooked brown rice, butter beans, kidney beans, and black beans. Stir until everything is evenly distributed.
Reduce the heat to low, cover the pot, and let it simmer for about 15-20 minutes. This allows the flavors to meld together beautifully.
Once the jambalaya is heated through, remove it from the heat. Stir in the freshly chopped cilantro and parsley. Serve warm, garnished with additional herbs if desired.