Make the caldo de “pollo”: In a large pot, melt the vegan butter over medium-high heat. Add the onion and garlic paste and sauté until fragrant, 2–3 minutes. Add the vegetable stock and bouillon cube and bring to a boil. Once the bouillon cube has dissolved, reduce the heat to low, add the bay leaves, and season with salt and the pepper. Simmer for 15–20 minutes, until the flavors marry.
Meanwhile, make the mojo: Dice the onion and red and green bell pepper. Transfer to a medium container with a lid and add the garlic paste, cilantro, and olive oil and season with salt and pepper. Stir to combine. Cover and refrigerate until ready to serve.
Make the mofongo: In a large, high-walled pan, heat the oil over medium-high heat until shimmering. Working in batches, add the plantain pieces to the hot oil and fry for 3–4 minutes, until golden brown on all sides. Transfer to a paper towel-lined plate to drain.
Add a few pieces of fried plantain, some vegan butter, and garlic paste, to a mortar. Mash with the pestle until smooth, adding 1 tablespoon at a time of the caldo until the desired consistency is reached. Season to taste with adobo seasoning. Repeat with the remaining plantains.
Use your hands or rubber spatula to shape the mofongo into roughly 1-cup mounds.
Top the mofongo with the mojo and serve immediately with the hot caldo alongside.