Thsi is the ultimate fuss-free dish; mushrooms and tomatoes can be roasted ahead of time and then quickly reheated to top the salad. Serve individually or on a platter. For perfect Parmesan curls, use a vegetable peeler!!
In a bowl, whisk together 3 tablespoons olive oil with the vinegar and thyme. Turn the mushrooms in the marinade to coat, cover and set aside (this can be done a few hours ahead.).
Preheat oven to 400°F Place the mushrooms on one side of parchemnt paper-lined baking sheet. Toss tomatoes in the remaining marinade and pour onto the other end of the baking sheet. Roast in center of oven for 12 minutes. Let cool slightly before slicing mushrooms in half. Reserve the juices from the baking sheet.
In a mixing bowl, toss the spinach and parmesan with the remaining olive oil and salt and pepper. Spread spinach mixture on a serving platter and top with roasted mushrooms and tomatoes. Just before serving, drizzle reserved juices overtop,.