1. Heat oil in a large non-stick frying pan. Add sausages. Cook, turning occasionally, until browned all over and cooked through. Drain on absorbent paper. Slice finely.
2. Add onions to same frying pan. Cook, stirring occasionally, until soft. Add sausages, lentils, pesto, water and parsley. Bring to boil. Season with salt and pepper. Remove from heat.
3. Combine sour cream and parmesan in a medium bowl. Stir well.
4. Arrange a quarter of the lasagne sheets over base of a large ovenproof, freezerproof dish (10-cup capacity). Spread a quarter sour cream mixture over lasagne sheets. Spread a third sausage mixture over sour cream. Repeat layering with remaining lasagne sheets, sour cream and sausage mixtures, finishing with sour cream. Sprinkle with tasty cheese.
5. Cover tightly with foil. Place on an oven tray. Cook in a hot oven (200C) for 40 minutes, or until tender. Remove foil. Cook uncovered for a further 15 minutes, or until cheese is browned. Stand for 5 minutes before serving.
6. Serve pasta with parsley.

To freeze: Make recipe to end of step 4. Cover tightly with plastic wrap. Label and date. Freeze for up to 2 months.

To serve: Thaw pasta in its dish in the refrigerator. Remove plastic wrap. Place on an oven tray. Cook in a hot oven (200C) for about 1 hour, or until hot. Remove foil. Cook uncovered for a further 15 minutes, or until cheese is browned. Stand for 5 minutes before serving. Finish step 6.