In a large skillet, melt 4 tbsp butter over medium heat. Add the shallot and cook until translucent.
Add sliced mushrooms, 1 tsp salt, and pepper. Cook for 1 minute, stir, then cover and cook for 5 minutes.
Uncover and increase to medium-high heat. Sauté for another minute.
Pour in Marsala wine and cook for 2 minutes to reduce.
Add stock, tarragon, parsley, 1 tsp salt, and 1 tsp lemon juice. Simmer for 25 minutes until sauce thickens.
Remove from heat, stir in remaining 3 tbsp butter (one at a time), and final 1 tsp lemon juice. Taste and adjust salt.
Meanwhile, cook pasta in salted boiling water until al dente. Reserve ½ cup of pasta water before draining.
Toss pasta with mushroom sauce and a splash of pasta water if needed.
Serve hot, garnished with parsley and grated cheese.