Step 1

For the pasta: Soak the dried porcini mushrooms in 1 cup hot tap water for 25 minutes to rehydrate.

Step 2

Lay the lasagna sheets out on a cutting board and cut into long strips about 1 1/2 centimeters (3/4-inch) wide.

Step 3

Meanwhile, in the bowl of a small food processor or a mortar and pestle, combine the basil, tarragon, Pecorino, walnuts and garlic and blitz to finely chop. Add the olive oil and season with salt and pepper and continue to blitz until well combined but still a bit textured.

Step 4

Heat the butter in a sauté pan over medium heat and add in the shallot. Season with salt and pepper and cook until tender and just slightly golden, about 3 minutes.

Step 5

Meanwhile, remove the porcini mushrooms from their liquid and reserve both. Gently squeeze the mushrooms to remove excess water and roughly chop. Add to the pan and continue to cook on medium heat until the mushrooms are lightly golden, about 2 to 3 minutes.

Step 6

Add the white wine and cook for 2 minutes, or until most of the wine has been absorbed. Pour 1/2 cup of the porcini steeping liquid into the pan, being careful to leave any grit that may have settled at the bottom of the liquid behind and discard the rest. Simmer until the liquid has reduced by about half.

Step 7

Place a large pot of water over high heat, season well with salt and bring to a boil. Cook the pasta for 2 to 3 minutes, or just until al dente. Reserving approximately 1 cup of cooking liquid, transfer the pasta from the pot directly into the mushroom mixture and stir in the herby pesto. Add a few tablespoons of the pasta cooking liquid to bring everything together and turn the heat down to low and allow the pasta to keep warm while you make the crunchy topping.

Step 8

For the topping: Melt the butter in a small skillet over medium-high heat. Add in the panko and cook, stirring constantly, until golden and crisp, about 1 minute. Transfer the panko to a small bowl and allow it to cool slightly before tossing in the Pecorino, lemon zest and herbs. Then season to taste with salt and pepper.

Step 9

Add a splash more of the pasta cooking liquid to the pasta if it seems a bit thick. Serve immediately sprinkled with the topping and additional Pecorino, if desired.