Begin by boiling a large pan of salted water. Once boiling, add your conchiglioni pasta and cook as per instructions until al dente.
Next, slice the Shroomdogs and fry in a small glug of oil turning every so often so all sides are cooked and turn crisp and golden. While the sausages are cooking move them over to one side of your frying pan and add in your sage leaves, allowing to crisp up in the hot olive oil. Remove once they turn dark green and drain on paper towels. Set to one side to garnish with.
For the pesto simply muddle all ingredients or blitz in a blender.
Once the pasta is cooked, combine with the sausages and pesto. Throw in the sage leaves, add freshly ground black pepper, finely grate over lemon zest and serve with a side of Gruyere.