Heat the oven or a toaster oven to 400°F.

• Peel and thinly slice the onion.
• Finely chop enough garlic to measure 1 teaspoon.
• Cut the potato in half, then cut the halves into ¼-inch-thick half-moons.
• Strip the kale leaves from their stems; coarsely chop the leaves.
• Rinse the white beans.
• Strip the parsley leaves from their stems; coarsely chop the leaves.

In a medium pot over medium heat, warm 2 tablespoons oil until hot but not smoking. Add the onion, garlic, and potato, and season with salt and as much of the Aleppo chile as you like. Cook, stirring occasionally, until the the potatoes are just beginning to soften, 3 to 5 minutes.
Add the kale, season lightly with salt, and cook just until the leaves start to wilt, 1 to 2 minutes.
Add the white beans ,4 cups water, and a pinch of salt. Bring to a boil, reduce to a simmer, and cook, stirring occasionally, until the potatoes are tender, 10 to 15 minutes. Remove from the heat and season to taste with salt and pepper.
While the soup cooks, prepare the cheese toasts.

• Slice the ciabatta roll in half lengthwise.

Put the ciabatta halves on a sheet pan and sprinkle them evenly with the cheddar cheese. Toast them in the oven until the cheese is melted and bubbling and the ciabatta is golden around the edges, 4 to 6 minutes.

Transfer the soup to individual bowls. Garnish with the parsley and serve with the cheese toasts on the side.

To get the soup to the table even more quickly, in Step 1, start cooking the onion, garlic, and potato while you prep the remaining ingredients.