Preheat the oven to 325°F (165°C) and lightly butter a 5x7-inch baking dish.
In a medium bowl, whisk the egg, milk, salt, cinnamon, nutmeg, sugar, and vanilla until smooth.
Stir in the peaches, pecans, and cooked rice.
Pour the mixture into the prepared dish and spread evenly.
Boil water in a kettle. Place the baking dish inside a larger pan (like a 9x13-inch pan), then pour the boiling water into the outer pan until it reaches halfway up the sides of the smaller dish—this is called a water bath and helps the pudding cook evenly. Tip: Place the larger pan on a rimmed baking sheet for easier handling.
Carefully transfer to the oven and bake for 50–55 minutes, until the pudding is set and lightly browned. Use caution when removing—it will be hot.
Let cool slightly. Serve warm, topped with whipped cream if desired.
Notes
Use Any Cooked Rice: White, brown, jasmine, or basmati rice all work well. Just make sure it's fully cooked before adding.
Break Up Clumps: If using cold or leftover rice, break up any clumps with your hands or a fork for even mixing.
Double Easily: To make a larger batch, double the ingredients and use an 8x8-inch baking dish.
Watch the Water Bath: Be careful when handling the hot water bath—use oven mitts and place the pan on a baking sheet for extra stability.
How To Toast Pecans:Pour 1/4 cup of chopped pecans into a small skillet over medium heat and stir the nuts in the pan until they are lightly toasted, about 3-5 minutes.