Mushroom and Spinach Lasagne
Creamy vegetarian lasagne layered with garlicky mushrooms, wilted spinach and a silky béchamel, baked until golden and bubbling.
30Prep min
55Cook min
85Total min
Serves 6Serves
ItalianCuisine
MediumDifficulty
A good lasagne should feel like a proper occasion, and this mushroom and spinach version delivers all of that without a scrap of meat. The mushrooms are cooked hard and long so they lose their water and turn deeply savoury, then folded through a garlicky béchamel that keeps everything creamy rather than watery.
Spinach comes in at the end, just long enough to wilt, so it stays bright and green against the pale sauce. Between the layers goes a mix of mozzarella and Parmesan, enough to bind but not so much that it overwhelms the mushrooms.
It bakes for about 40 minutes, rests for 10, and then slices cleanly. Serve it with a sharp dressed salad and you have a Sunday lunch or a make-ahead dinner that genuinely improves the next day.
Spinach comes in at the end, just long enough to wilt, so it stays bright and green against the pale sauce. Between the layers goes a mix of mozzarella and Parmesan, enough to bind but not so much that it overwhelms the mushrooms.
It bakes for about 40 minutes, rests for 10, and then slices cleanly. Serve it with a sharp dressed salad and you have a Sunday lunch or a make-ahead dinner that genuinely improves the next day.
Ingredients
- 3 tablespoons olive oil
- 1 kg (2 lb 4 oz) chestnut or cremini mushrooms, wiped and sliced 5 mm thick
- 1 large onion, finely chopped
- 4 garlic cloves, finely chopped
- 1 tablespoon fresh thyme leaves
- 1 teaspoon fine salt, plus more to taste
- 1/2 teaspoon freshly ground black pepper
- 60 ml (1/4 cup) dry white wine or vegetable stock
- 250 g (9 oz) baby spinach
- 90 g (6 tablespoons) unsalted butter
- 90 g (3/4 cup) plain flour
- 900 ml (3 3/4 cups) whole milk, warmed
- 1/4 teaspoon freshly grated nutmeg
- 150 g (1 1/2 cups) mozzarella, grated
- 80 g (3/4 cup) Parmesan, finely grated
- 12 dried lasagne sheets (about 250 g / 9 oz), regular or no-boil
- Extra butter or olive oil for the dish
Instructions
- Heat 2 tablespoons of the olive oil in a wide, heavy pot over high heat. Add half the mushrooms with a pinch of salt and cook, stirring only occasionally, for 6-8 minutes until they squeak, release their water and then brown. Tip into a bowl. Repeat with the remaining oil and mushrooms.
- Lower the heat to medium, add the onion to the same pot with a splash more oil if needed, and cook for 6 minutes until soft and translucent. Add the garlic and thyme and cook for 1 minute until fragrant.
- Return all the mushrooms to the pot, pour in the wine or stock and scrape up anything stuck to the base. Cook for 3-4 minutes until the liquid has almost entirely gone. Season with 1/2 teaspoon of the salt and the pepper, then set aside off the heat.
- For the béchamel, melt the butter in a separate saucepan over medium heat. Whisk in the flour and cook for 2 minutes, whisking constantly, until it smells biscuity but has not coloured.
- Pour in the warm milk in a steady stream, whisking hard to keep it smooth. Cook for 6-8 minutes, whisking often, until the sauce thickly coats the back of a spoon. Season with the remaining 1/2 teaspoon salt and the nutmeg.
- Stir two-thirds of the béchamel into the mushrooms. Put the spinach in a large colander, pour over a kettle of just-boiled water to wilt it, then press firmly with the back of a spoon to squeeze out as much water as you can. Chop roughly and fold into the mushroom mixture. Taste and adjust the salt.
- Heat the oven to 190°C fan / 210°C / 410°F. Butter a 23 x 33 cm (9 x 13 inch) baking dish.
- Spread a thin layer of the plain reserved béchamel over the base. Add 4 lasagne sheets in a single layer, breaking one to fit if needed. Spread over half the mushroom and spinach mixture, then scatter with a third of the mozzarella and a third of the Parmesan.
- Repeat with 4 more sheets, the remaining mushroom mixture and half of what remains of the cheeses. Finish with the last 4 sheets, the remaining béchamel spread right to the edges, and the last of the mozzarella and Parmesan.
- Cover with foil, tenting it so it does not touch the cheese, and bake for 25 minutes. Remove the foil and bake for a further 18-20 minutes until the top is deeply golden in patches and the edges are bubbling.
- Rest on a wire rack for 10 minutes before cutting, so the layers hold together. Cut into 6 generous squares.
Cook’s tips
- Cooking the mushrooms in two batches is the single most important step - crowded mushrooms steam instead of browning, and wet mushrooms make a wet lasagne.
- If using no-boil sheets, add an extra 100 ml milk to the béchamel so there is enough liquid for the pasta to hydrate.
- Let the béchamel cool slightly before mixing with the mushrooms so the spinach keeps its colour.
Substitutions
- Swap half the mushrooms for rehydrated porcini, using the soaking liquid in place of some of the milk.
- Use a good melting vegan mozzarella and oat milk béchamel with a dairy-free butter to make it vegan.
- Frozen spinach works fine - thaw 300 g, squeeze it very dry, and skip the kettle step.
Storage & reheating
Cool leftovers within 2 hours, refrigerate in a covered dish for up to 3 days and reheat, covered, at 180°C for 20-25 minutes; it also freezes well for up to 2 months, thawed overnight before reheating.
Frequently asked questions
Can I assemble this lasagne ahead of time?
Yes. Build it up to the point of baking, cover and refrigerate for up to 24 hours. Add 10 minutes to the covered baking time because it goes into the oven cold.
Why is my lasagne watery?
Almost always the mushrooms or spinach. Brown the mushrooms properly so their water evaporates, and squeeze the wilted spinach hard in a colander or clean tea towel before folding it in.
Do I need to pre-cook the lasagne sheets?
No. Regular dried sheets soften in the oven from the moisture in the béchamel and mushrooms. No-boil sheets work too, but add 100 ml extra milk to the sauce.
Can I make this gluten free?
Yes, use gluten-free lasagne sheets and swap the flour in the béchamel for cornflour, using 60 g instead of 90 g and cooking it out for 1 minute before adding the milk.
