Preheat the oven to 350F. Heat a heavy based pot over a medium high heat, drizzle in some olive oil and then add the sausage meat to brown for 5-8 minutes.

Add the onion, garlic, mushrooms, baby spinach, and fennel seeds into the pot and saute for another 5 minutes until the mushrooms are browned and the spinach is wilted. Set it aside to cool a little

For the white sauce, melt butter, toss in flour, mix them until a smooth roux forms, then gradually add milk. Don't forget to sprinkle nutmeg and seasoning salt while stirring until the sauce thickens.

Add the ricotta and 1 ½ cups of the mozzarella into the pot and mix.

Now it's time to layer your lasagna- starting with white sauce, then lasagna sheets, and finally the meat sauce. Go for three repeats in a 9x9 inch casserole dish.