Mushrooms are an optional, not traditional, component.
Many vegan lasagna recipes add mushrooms: they provide a meaty, umami falvour – but mushrooms are not filling. If you want to add mushrooms for flavour you can make duxelles. Duxelles is made from finely chopped mushrooms and shallots, with herbs, and deeply cooked. You might know it from beef wellington recipes.
When assembling the lasagna, add it after the ragu layers. If you are making this lasagna for someone else, ask if they like mushrooms first!
Chop the mushrooms finely, ideally with a food processor.
Pre-heat a large pan on medium-high heat. Add the olive oil and when it’s shimmering and fluid add the mushrooms, shallots, garlic, thyme, salt, and pepper. Cook, stirring often, for 10–15 minutes until the mushrooms and shallots have softened and begun to brown.
Add the red wine to deglaze the pan, allow it to cook for about 30 seconds, then remove from heat.
You can prepare keep duxelles in the fridge for 3–5 days.
Duxelle is excellent to keep on hand, it can be added quickly to rice or omelettes for a fast meal, on crostini for an appetizer, or added to any pasta dish.
You can use any kind of mushroom, cremini is easily available. If you can find fresh shiitake or oyster mushrooms they will add a tremendous depth of flavour.