Bring a medium saucepan of salted water to the boil for the pasta. Halve the leek lengthwise and rinse under running water to remove any hidden dirt. Thinly slice the leek, discarding any dark green stem. Crush or finely chop the garlic. Halve the olives.
Step 2 — Start sauce
Heat 2 tsp olive oil in a medium deep frypan over medium-high heat. Cook the leek, garlic and 1½ tsp Tuscan seasoning*, stirring regularly, for 3 mins. Add the olives, tomatoes, half the tomato paste*, ½ tsp sugar, 1 tsp balsamic vinegar and 60ml (¼ cup) water to the leek mixture. Reduce heat to medium and cook, covered, for 10 mins to develop the flavour.
Step 3 — Finish prep
Meanwhile, coarsely chop the spinach. Coarsely chop the oregano, discarding the stems. Chop the capers.
Step 4 — Cook pasta
Cook the pasta in the pan of boiling water for 10 mins or until al dente. Reserve 60ml (¼ cup) cooking water, then drain the pasta.
Step 5 — Finish sauce
Add the spinach, oregano and capers to the sauce and cook, stirring and squashing the tomatoes with the back of a wooden spoon to release juices, for 2 mins or until the spinach is wilted. Taste, then season with salt and pepper.
Step 6 — Get ready to serve
Add the pasta to the sauce. Gradually add the reserved cooking water, stirring constantly, until the sauce coats the pasta. Divide the pasta among bowls and drizzle with 2 tsp extra virgin olive oil to serve.