Preheat the oven and prepare the cauliflower - Preheat the oven to 425°F (220°C) and line a baking sheet with parchment paper. Rinse the cauliflower and remove the leaves and stem. Cut the cauliflower into small florets, about the size of a quarter. Place the florets on the prepared baking sheet. - Be sure to dry the cauliflower florets well after rinsing them, to ensure that they get crispy when roasted. If you prefer, you can use frozen cauliflower florets instead of fresh ones, but be sure to thaw them completely and pat them dry before using.

Season and roast the cauliflower - Drizzle the cauliflower with 2 tablespoons of olive oil and sprinkle with 2 teaspoons of paprika. Season with salt and pepper to taste, and toss until the cauliflower is evenly coated with oil and spices. Roast in the preheated oven for 20-25 minutes, or until golden brown and crispy, flipping once halfway through cooking. - Do not overcrowd the baking sheet, or the cauliflower will steam instead of roasting and become soggy. Instead, use multiple baking sheets if necessary to ensure that the cauliflower is spread in an even layer. Adjust the cooking time depending on your oven and the desired level of crispiness.

Prepare the lime slaw - In a mixing bowl, whisk together the juice of 1 lime, 2 tablespoons of olive oil, and salt and pepper to taste, until well combined. Add 2 cups of shredded cabbage and 1/2 cup of sliced red onion to the bowl, and toss the mixture until the cabbage and onion are evenly coated with the lime dressing. - Feel free to add other finely chopped veggies to the slaw, such as carrots, bell peppers, or radishes, for extra crunch and color. Adjust the seasonings to taste, and add honey or agave nectar for a touch of sweetness if desired.

Warm up the taco shells and assemble the tacos - Warm up 8 taco shells in the oven or on the stovetop according to package instructions. Once warmed, fill each taco shell with a spoonful of black beans, a few pieces of the roasted cauliflower, a scoop of the lime slaw, a couple of slices of avocado, and a sprinkle of chopped cilantro. Serve the tacos immediately and enjoy! - If you prefer, you can use flour or corn tortillas instead of taco shells, and heat them in the oven or on a dry skillet until soft and pliable. Feel free to customize the toppings to your liking, such as adding hot sauce, salsa, or vegan cheese to the tacos.