It is usually prepared with pasta mista (pasta ammescata in Neapolitan dialect), which has recently been produced industrially as a distinct variety of pasta, but which was once sold cheaply by weight, made up of odd broken pieces of various different shapes of pasta.
The traditional cooking method for this kind of soup consists in cooking the condiments first, making the base of the soup, then throwing in the pasta. While cooking with all the other ingredients, the pasta retains precious starches, which would have been lost if normally cooked separately in salty water and then drained. Cooking pasta together with vegetables makes the sauce creamier; as a bonus, adding the secret ingredient* makes this a 100% authentic cucina povera specialty.
500 g (1.1 lb) russet potatoes (best if old!), peeled and cubed
1 glass of extra virgin olive oil
1/2 white onion, minced
1 celery rib, minced
1 quart of beef broth
*200 g (1 cup) smoked provola, diced (can be substituted with any smoked semi-soft cheese)
1 garlic clove, minced
Salt and freshly ground black pepper to taste
Heat the oil in a large stewpot equipped with a tight fitting lid. Sauté the onion and garlic and when they begin to tan, add the celery, simmer lightly, and season with salt and pepper.
Pour in 2 ladles of stock and add the cubed potatoes. Gently simmer over medium-low heat, and bear in mind the potatoes mustn’t purée.
Add the raw pasta and cook as you would risotto, ladling in broth a little at a time as it absorbs. The degree of thickness is determined by this key step. Too much stock will make your soup too liquid, too little will result in a soggy "neither fish nor flesh" dish. Keep hearty Italian minestre like Ribollita in mind as a texture model.
When the pasta is cooked through, rank up the heat and toss in the diced smoked cheese, stirring constantly. Cover and let the cheese melt and form lovely long springy ribbons.