Cook the squid ink pasta in a large pot of salted boiling water according to the package instructions until al dente. Drain and set aside, reserving a cup of the pasta cooking water.
Cook the Prawns:
In a large skillet, heat the olive oil over medium-high heat. Add the prawns and cook until they turn pink and are cooked through, about 2-3 minutes per side. Remove the prawns from the skillet and set aside.
Make the Sauce:
In the same skillet, add the minced garlic and chopped shallot. Sauté until fragrant and translucent, about 2 minutes.
Pour in the white wine and let it simmer until reduced by half.
Add the fish or seafood stock and let it simmer for another 2-3 minutes.
Stir in the heavy cream and let it simmer until slightly thickened, about 5 minutes.
Add the grated Parmesan cheese, stirring until melted and the sauce is smooth.
Season with salt and freshly ground black pepper to taste.
Stir in the lemon juice and chopped parsley.
Combine Pasta and Sauce:
Add the cooked pasta to the skillet with the sauce. Toss to coat the pasta evenly in the sauce. If the sauce is too thick, add a bit of the reserved pasta cooking water until the desired consistency is reached.
Finish the Dish:
Return the cooked prawns to the skillet and gently toss to combine and warm through.
Add the butter and stir until melted and incorporated.
If using fresh truffle, shave thin slices over the pasta just before serving. If using truffle oil, drizzle it over the pasta.
Serve:
Divide the pasta among serving plates, ensuring an even distribution of prawns.
Garnish with additional parsley and a few more truffle shavings or a light drizzle of truffle oil.