Brown mince in medium to large pot, drain fat, add onion and mushrooms, stir and cook for 5 to 10 minutes. Turn up heat and add red wine, boil for a few minutes to burn off alcohol. Add salt and pepper, crush OXO cube, garlic, passata and stir. Bring to the boil and then turn down to simmer. Simmer for 15 - 20 minutes. Stir regularly; season with salt and pepper.
While Bolognese sauce is cooking, place butter in medium sized pan on a medium/low heat and melt butter, add flour a dessertspoon at a time and stir, keep stirring and adding flour till you get quite a thick golden-coloured mix. You may not need all the flour or you may need a little more. Add milk a little at a time and keep stirring. When you have a nice thick white sauce, add the paprika, bouillon, salt and pepper. Turn down heat to simmer and keep stirring. Make sure you scrape the bottom and edges of the pan to stop the white sauce from catching. Simmer for 5 minutes.
Take a lasagne dish and place a little of the Bolognese sauce over the bottom, top with lasagne sheets then put some of the white sauce on top. Next put Bolognese sauce on top of white sauce and cover with lasagne sheets and repeat. Finish with white sauce. Cover the top with grated Parmesan cheese.
Put dish in oven in middle shelf for 35 - 40 minutes. When the top is golden and bubbling it is ready to eat. Enjoy.
Serve with garlic bread or salad.
If you can, leave it till next day before cooking as it tastes even better.