Grate the cheddar and Parmesan, clean and chop the white mushrooms into pieces, finely chop the onion, wash and dry the spinach thoroughly, cut the cold unsalted butter into cubes, and measure out the flour and cream. Set all ingredients aside.

In a large bowl, mix the flour with a pinch of salt. Add the cold butter cubes and cut or rub together with two knives or your fingertips until the mixture resembles coarse crumbs. Add ice-cold water one spoonful at a time until the dough just comes together. Quickly form a disk, wrap in plastic wrap, and chill in the refrigerator for 20–30 minutes.

Set the oven to 375 °F once the dough is in the refrigerator, so the oven is ready by the time you blind bake.

Lightly dust a work surface with flour and roll out the chilled dough into a circle about 12 inches in diameter. Line a tart or quiche pan with the dough, press it against the sides, and trim away any excess. Prick the bottom several times with a fork.

Line the base with parchment paper and fill with baking beads or dried beans. Bake for 12–15 minutes until the edges begin to color. Remove the parchment and weights and bake for another 5 minutes until the bottom is lightly golden brown. Remove from the oven and set aside to cool slightly while you make the filling.

Heat a splash of olive oil in a large frying pan over medium heat. Add the chopped onion and cook for 3–4 minutes until soft and translucent. Add the white mushrooms and cook for about 5 minutes until browned. Add the spinach and cook for another 1–2 minutes until wilted. Season with salt and pepper and remove from the heat.

Place tofu, cream, the grated cheddar, mustard, garlic powder, and ground nutmeg in a blender or tall bowl and blend until smooth and creamy. Taste and season with salt and pepper if needed.

Heat a splash of olive oil and fry the bacon cubes until crispy.

Spread the cooked vegetables evenly over the pre-baked crust. Pour the tofu-cream mixture over the top and scatter the fried bacon cubes over it. Smooth the surface and sprinkle with grated Parmesan.

Bake the quiche for 30–35 minutes in the preheated oven until the filling is set and lightly golden brown. Let the quiche cool in the pan for 5–10 minutes before removing it from the pan and slicing. Enjoy!