Preheat oven to 200C. Line a baking tray with baking paper. Place the pumpkin on the tray. Sprinkle with the sage. Spray with olive oil spray and season. Roast, turning occasionally, for 20-25 mins or until pumpkin is tender.
Meanwhile, heat a large non-stick frying pan over medium heat. Cook the leek, stirring occasionally, for 5 mins or until leek softens. Add the carbonara sauce and bring to a simmer.
Cook ravioli in a saucepan of boiling water following packet directions or until al dente. Drain well.
Add to the leek mixture with pumpkin mixture. Toss to combine. Divide among serving bowls. Season with pepper.