Dice the shallot and carrot, then slice the celery stalks.

Mince the garlic cloves and roughly chop the baby potatoes.

Peel the baby potatoes if making the crispy topping, reserving all potato skins.

Spread the reserved potato skins and crumbled stale bread on a baking tray.

Bake the potato skins and bread at 150°C (300°F) for 10 minutes until dry and crisp.

Heat the olive oil in a large saucepan over medium heat, then add the diced shallot, carrot, celery, and minced garlic.

Sauté the vegetables for 5 to 7 minutes until soft, stirring regularly.

Add the sherry vinegar, drained butter beans, chopped potatoes, fregola pasta, tomato paste, and black pepper to the saucepan.

Stir the mixture and cook for 2 minutes to coat the ingredients with tomato paste.

Dissolve the miso paste in the 175 ml hot water to make a miso broth.

Pour the miso broth into the saucepan, then bring the soup to a gentle simmer.

Simmer the soup for 20 minutes until the potatoes are tender and the fregola is cooked.

Blend the soup with an immersion blender for a few seconds if a creamier texture is desired.

Add the kale to the simmering soup, then cook for 2 minutes until wilted.

Pulse the baked potato skins and toasted bread in a food processor to make coarse crumbs.

Heat the remaining olive oil in a frying pan, then fry the crumbs until golden brown.

Remove the crumb topping from the heat, then stir in the chopped fresh chives.

Ladle the soup into four bowls and top each serving with crispy potato skin crumbs.

Finish each bowl with a squeeze of lemon juice or a sprinkling of lemon zest.