Bring a medium saucepan of salted water to the boil for the pasta. Finely chop the onion. Crush or finely chop the garlic. Tear the kale leaves into small pieces, discarding the stems. Thinly slice the sausages on an angle. Crumble 1 stock cube* into a heatproof jug, add 200ml boiling water and stir to dissolve.
Step 2 — Cook sausage
Heat 2 tsp olive oil in a medium deep frypan over medium-high heat. Cook the sausage, turning regularly, for 6-8 mins until golden and cooked through. Remove from the pan with tongs, leaving the flavoured oil in the pan.
Step 3 — Start sauce
Add the onion and garlic to the same pan and reduce the heat to medium. Cook, stirring, for 3-4 mins until the onion is softened.
Step 4 — Cook pasta
Meanwhile, cook the pasta in the pan of boiling water for 10 mins or until al dente. Drain.
Step 5 — Simmer sauce
Add the sausage, Italian seasoning, stock, tomatoes and ½ tsp sugar to the onion mixture. Stir to combine and bring to a simmer. Add the kale and cook, stirring occasionally, for 5-6 mins until the sauce is thickened and the kale is tender.
Step 6 — Get ready to serve
While the sauce is cooking, finely grate the parmesan. Add the pasta, half the parmesan and 1½ tsp balsamic vinegar to the sauce and stir until combined. Divide the pasta among bowls. Scatter over the remaining parmesan to serve.