Bring a large pot of generously salted water to a rolling boil for the pasta.

Pat the sage leaves completely dry with kitchen paper. Heat 50g of butter with the olive oil in a large, deep frying pan over medium heat until the butter begins to foam.

Add the sage leaves in a single layer and fry for 30-45 seconds per side until crispy but still green. Remove with a slotted spoon and drain on kitchen paper, reserving the butter in the pan.

Increase heat to medium-high, add the sliced mushrooms to the same pan in a single layer, and cook undisturbed for 3-4 minutes until golden underneath. Stir and cook for another 3-4 minutes until tender and caramelised. Season with salt and pepper, then transfer to a plate.

Reduce heat to medium, add the remaining 50g butter to the pan. Once melted, add the shallot and cook for 2 minutes until softened. Add the garlic slices and cook for 1 minute until fragrant but not browned.

Continue cooking the butter, swirling occasionally, for 2-3 minutes until it turns a golden amber colour and smells nutty. Remove from heat immediately to prevent burning.

Meanwhile, cook the tagliatelle in the boiling water according to packet instructions until al dente. Reserve 150ml of pasta cooking water before draining.

Add the drained pasta directly to the brown butter pan along with the mushrooms and 100ml of reserved pasta water. Toss vigorously over low heat for 1-2 minutes until the sauce coats the pasta, adding more pasta water if needed.

Remove from heat and stir in the Parmesan, lemon juice, and nutmeg. Season to taste with salt and pepper.

Divide among warm serving bowls, top with crispy sage leaves, extra Parmesan, and fresh parsley. Serve immediately.