Tarts are so versatile. In the fall and winter, we love to use mushrooms or potatoes or sliced eggplant, but in the spring and summer, we may make the same basic tart using zucchini and tomato or thinly sliced peppers. We may substitute ricotta for the goat cheese or balsamic for the champagne vinegar or trade out the thyme for rosemary. And don't feel as if you need to be overly concerned about making a pretty crust -- a rustic galette is just as tasty. The combinations are endless.
That said, we love this mushroom tart! The baked mushroom slices are perfectly meaty, the thyme works its special little magic, and the goat cheese adds the right amount of creaminess to bring it all together. The beauty of this dish is that it is just as good room temperature as it is hot. Make it ahead of time and serve a slice for lunch, or pair it hot out of the oven with a nice little salad for a light dinner.