Curried Potato Tart with Cilantro Yogurt

Name: Curried Potato Tart with Cilantro Yogurt
Ingredients: 8 green cardamom pods; 2 teaspoons coriander seeds; 1 medium onion, chopped; 6 garlic cloves, thinly sliced; 1 jalapeño, thinly sliced; 6 tablespoons unsalted butter; ¼ cup olive oil; 1 tablespoon brown mustard seeds; 1 tablespoon Madras curry powder; Kosher salt, freshly ground peppe; 3 pounds red-skinned potatoes, scrubbed; Kosher salt; 1 10-ounce package frozen spinach, thawed; 1 cup thawed frozen peas; ½ cup heavy cream; 1 ½ cups plain whole-milk Greek yogurt, divided; Freshly ground black pepper; 6 14x12-inch sheets frozen phyllo pastry, thawed; 1 small garlic clove; 1 cup cilantro leaves with tender stems; 2 tablespoons fresh lime juice; A spice mill or a mortar and pestle