Vegan Tempeh-Filled Plantain Cups (Tostones Rellenos)

These Vegan Tempeh-Filled Plantain Cups, also known as Tostones Rellenos, are made by filling plantain cups with well-seasoned tempeh. The tempeh is cooked with flavorful spices and then stuffed into fried plantains before being topped with avocado, pickled red onion, and cilantro.