Ruth’s Chris Mushroom & Gruyère Tart – Elegant Appetizer

Instructions:

1. Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper.
2. Lightly roll out the puff pastry and place it on the baking sheet. Score a 1-inch border around the edges, being careful not to cut all the way through.
3. Heat olive oil and butter in a skillet over medium heat.
4. Add the mushrooms and cook for 8–10 minutes, until softened and lightly browned.
5. Stir in the garlic, thyme, salt, and black pepper. Cook for 30 seconds, then remove from heat.
6. In a small bowl, whisk together the egg, heavy cream, and Dijon mustard until smooth.
7. Spread the mushroom mixture evenly inside the scored pastry border.
8. Sprinkle the Gruyère cheese over the mushrooms, then drizzle the cream mixture evenly on top.
9. Bake for 25–30 minutes, until the pastry is puffed and golden and the filling is bubbly.
10. Garnish with fresh thyme or parsley, slice, and serve warm.

Variations

• Add caramelized onions for extra sweetness and depth.
• Substitute Gruyère with Fontina or Comté for a slightly different flavor profile.
• Include a handful of sautéed spinach for a greener version.
• Finish with shaved Parmesan just before serving for added sharpness.

Tips

• Sauté mushrooms until their moisture has fully cooked off to prevent a soggy tart.
• Use freshly grated cheese for the smoothest melt and best flavor.
• An egg wash on the pastry edges creates a deeper golden finish.
• This tart can be baked slightly ahead and reheated gently before serving.