In a large pot over low-medium heat, add 1-2 tbsp of olive oil (or use water to saute). Once heated, add the diced red onions and minced garlic. Season with salt and pepper to taste. Saute until onions are translucent and garlic is fragrant.
Add in all other ingredients and stir to combine. Increase temperature to bring to a low boil.
Cover the pot with a lid and let simmer over low heat for at least 45 minutes or longer if desired.