In a large pot/pan, heat some oil and fry the onions until translucent (about 5 minutes). Add the garlic and fry for another minute before adding the mushrooms. Allow the mushrooms to brown slightly and add the tomatoes, tomato paste, chicken stock, thyme and chilli and allow to simmer for about 10 minutes. If the sauce needs to be thickened (it needs to coat the back of a spoon), add the cornflour mix and allow to thicken. Season to taste.
For the Bechamel, In a medium saucepan, melt butter over medium.Add flour and salt; cook, stirring frequently, until mixture is pale golden, about 5 minutes.Whisking constantly, pour in 2 cups milk; add 2 more cups milk and whisk until smooth. Cook mixture, stirring constantly along the bottom of pan, until boiling, about 7 minutes. Reduce heat to low. Simmer gently, stirring occasionally, until sauce thickens and does not feel grainy when a very small amount is rubbed between two fingers, about 10 minutes.To assemble:
Spoon 1/4 of the mushroom sauce into a baking dish and spread to cover the base. Add a layer of Lasagna sheets, top with more mushroom sauce and some of the Bechamel. Continue layering until all the sauce is used. Top with Grated Mozzarella and bake in a 170°C oven for 1 hour or until a knife can be inserted easily with no resistance.
For more wonderful recipes from Ally, visit her blog Simply Delicious