Preheat the oven to 375º. To prepare the plantain, slice off both tips, then make a vertical slit along the length of the plantain and peel. Slice into 1/4 inch slices at a 45 degree angle. Place on greased parchment paper on a baking sheet, brush with olive oil and salt lightly. You may need 2 pans to fit all 4 plantain. Bake for approximately 10 minutes, then flip and continue to bake until golden and slightly crispy, about 10-15 minutes longer.
To prepare the black bean sauce: in a large pan, heat the olive oil on medium heat and add the onion and garlic. Sauté 2-3 minutes until the onion is translucent.
Add the black beans, cumin and 1/2 cup of water. Bring to a simmer, then lower the heat and cook with the lid on for about 20 minutes. Add salt and pepper to taste.
Mash approximately half of the beans with the back of a wooden spoon for a creamier consistency. You are looking for a gravy like, yet lumpy texture. If the beans are dry, add a little more water.
To assemble: divide the plantain slices amongst 4 bowls. Top with the black bean sauce, cheese curds (or queso fresco) and cilantro, evenly divided on each poutine. Serve immediately.