Simmer broccolini in approximately 2 quarts of salted hot water for a few seconds.
Add uncooked spaghetti and cook for 8 minutes.
Put mushrooms and tomatoes in bottom of serving bowl.
Drain broccolini and spaghetti in colander and put on top of vegetables in bowl and let it sit for a minute.
Add Parmesan, butter, olive oil, lemon juice, salt and pepper; toss together and serve with some additional Parmesan grated on top.