Sweet Potato and Spinach Lasagne

500g Sweet Potato, peeled and sliced
2 bunches English spinach, washed
500g reduced-fat ricotta
1 bunch Shallots, sliced
½ cup chopped parsley
12 sheets instant lasagne, softened in hot water
425g jar tomato pasta sauce

Topping:
2 eggs
2 tablespoons plain flour
2 cups low-fat milk
Pinch pepper and ground nutmeg to taste
½ cup grated Parmesan or Romano cheese

Preheat oven to 180 °C.
Steam the Sweet Potato for 3 minutes, then cool.
Plunge spinach into boiling water until wilted and drain well to remove excess liquid.
In a large bowl combine drained spinach, ricotta, shallots and parsley.
Arrange 3 sheets of lasagne on the base of an ovenproof pan (33cm x 23cm).
Top with 1/3 each of sweet potato, tomato sauce and spinach ricotta mixture.
Repeat twice and top with remaining lasagne sheets.

To make topping, break eggs into flour and mix well to remove lumps.
Whisk in milk, pour into a saucepan and bring to the boil, whisking until smooth and thickened.Add pepper, pour over top of lasagne and sprinkle with cheese.
Bake for 30 minutes or until golden brown.