Savory Egg Pudding

Ingredients

• 1/4 cup all-purpose flour
• 1 cup half-and-half
• 3 large eggs
• 1 large egg yolk
• 1 cup heavy cream
• 2 medium red potatoes, halved lengthwise and thinly sliced (about 2 1/2 cups)
• 2 tablespoons fresh Italian parsley, finely chopped
• 2 teaspoons fresh tarragon, finely chopped
• 1 teaspoon finely grated lemon zest
• 2 tablespoons unsalted butter
• 2 medium leeks, white and pale green parts only, halved lengthwise, rinsed, and thinly sliced crosswise
• 1 medium garlic clove, peeled and minced