Preheat your oven to 160 °C and line a baking sheet with parchment paper. If using an air fryer that needs preheating, do this now.
Drain the can of beans and rinse the beans thoroughly under cold water. This helps remove excess starch and improves their crispiness.
470 g cooked butter beans
Place the butterbeans on a clean kitchen towel or paper towels and gently pat them dry. It's important to remove as much moisture as possible to achieve crispy results.
In a medium bowl, combine the dried butterbeans with olive oil, miso paste, paprika, salt and pepper. Toss the beans and gently massage with your fingers until they are evenly coated with the seasoning mixture.
1 tablespoon olive oil, 1 teaspoon paprika, 1 tablespoon white miso paste, 1 teaspoon flaky sea salt, ¼ teaspoon ground black pepper
Spread the seasoned butterbeans in a single layer on the prepared baking sheet. Make sure they are not overcrowded; you want them to roast, not steam. If using an air fryer, spread in one layer in the basket of your machine.
Place the baking sheet in the preheated oven (or place the tray in the air fryer) and roast the butterbeans for 30-25 minutes, shaking the tray half way through, or until very crispy and golden brown. If air frying, this will take around 25-30 minutes.
Remove from the oven or air fryer and leave to cool completely.