Preheat oven to 400°. Remove the leaves from the cauliflower, then trim the stem flush with the bottom of the head so the cauliflower sits flat in the Dutch oven and the lid can be closed tight. Place the cauliflower in the Dutch oven.
In a small bowl, mix together the 1/2 cup olive oil, Adobo sauce, garlic powder, onion powder, oregano, cumin, salt, and pepper. Spread the mixture over the cauliflower and rub, with your hands, until the sauce is in all nooks and crannies. Pour the vegetable broth at the bottom of the Dutch oven. Place the lid, pop in the oven for 45 minutes. Remove from the oven and add the beans and the minced onions on the sides of the cauliflower. Put back in the oven and cook, uncovered this time, for an additional 7 minutes. Remove from the oven and let rest for 10 minutes. Garnish with fresh cilantro and lime quarters. Bon appétit!