Using a large pot or deep pan, heat the oil over a moderate heat. Fry the anchovies (if using) and garlic until the anchovies are dissolved (about 1-2 minutes)
Add tomato concentrate and stir well then add the chickpeas and stir again.
Pour in the stock/broth and the rosemary sprig and simmer for 10 mins
Add the pasta and cook partially covered to the pasta packet timings. The pasta should be bubbling gently, so adjust the heat to ensure it doesn't cook too vigorously. Stir regularly to avoid the pasta sticking. Add a little more broth/stock or water if the liquid reduces too much.
Remove from the heat, season with salt - no more than 1tsp as both the broth/stock and anchovies will bring some level of salt. Finally, grind over some pepper to your liking. Fish out the rosemary sprig and discard and you're good to go.
To serve, drizzle with a little extra virgin olive oil and a grind of black pepper. You can also add a little finely grated Parmigiano Reggiano or Pecorino cheese if you wish.
Notes
Variations and suggestions:
Vegetarian / Vegan / Meat: Traditional versions are often vegan by omitting anchovies. For a meatier option, replace anchovies with pancetta or guanciale.
Herbs: Rosemary can be swapped for bay leaf, thyme, oregano or marjoram.
Pasta shapes: Ditalini is ideal, but tubetti, fregola, quadrucci or risoni (orzo) all work well. Broken long pasta (spaghetti or linguine) is also traditional. Mixed pasta can be used — cook to the longest required time.
Gluten-free pasta: Works well, but add extra broth as needed and stir more often to prevent sticking.
Serving & Storage (Notes)
Serve immediately for best texture.
Leftovers keep in the fridge for 1–2 days; the pasta will soften but flavour remains.
Freezing: Can be frozen in portions, though texture will soften when reheated. Add a splash of water or stock when reheating to loosen.
To serve: Traditionally finished with black pepper and extra virgin olive oil.
Optional: Grated Pecorino or Parmigiano Reggiano (not traditional, but very good).