Cook the tagliatelle in salted water with the olive oil until firm to the bite, drain, rinse, drain well and prepare.
Peel the onion, chop it finely and sweat it in olive oil until translucent. Clean the mushrooms, cut into slices and drizzle with the lemon juice. Add to the onion and sweat with it. Dice the ham, add it and sauté briefly.
Pour in the white wine and cream. Refine with tomato paste. Season the sauce with salt, pepper, cayenne pepper and sugar, bring to the boil once. Pull the parmesan into the sauce.
Add the tagliatelle, heat briefly, arrange, garnish and serve.