I could bake and eat this tart once a week since I am totally addicted to Gruyère. Make sure to get real Swiss Gruyère, or the tart just won’t have the right flavor. Sharp cheddar makes a good substitute.
1bunchscallions (green onions), white part and about half the green, thinly sliced
Set a rack in the lowest level of the oven and preheat to 350°F (180°C).
Melt the butter in a small sauté pan over medium heat and add the scallions. Cook, stirring occasionally, until wilted, 3 to 4 minutes. Scrape the scallions into a small bowl and set aside to cool for a few minutes.
Distribute the cooked scallions evenly over the tart crust, then sc