Easy hand-rolled spinach and ricotta cannelloni

Ingredients

• 2 sheets fresh lasagne
• 1 onion, finely diced
• 2 tablespoon olive oil
• 3 clove garlic, finely chopped
• 400 gram can crushed tomatoes
• 250 gram ricotta
• 100 gram parmesan, grated
• 200 gram fresh spinach or silverbeet, steamed and water squeezed out
• 1 egg, lightly beaten
• zest of 1 lemon
• 1/4 cup walnuts, toasted
• pinch of black pepper
• 1/4 teaspoon salt