Zucchini, Tomato and Potato Tian | The Kitchen Scout

Ingredients

• Olive oil
• 2 large yellow onions, cut in half and sliced
• 2 garlic cloves, minced
• 3/4 pound zucchini
• 1 1/4 pounds medium tomatoes
• 1 pound medium round potatoes, unpeeled (Yukon golds work well)
• 1 teaspoon kosher salt
• 1/2 teaspoon freshly ground black pepper
• 1 Tablespoon fresh thyme leaves, plus extra sprigs
• 2 ounces Gruyere cheese, grated