Leftover mashed potatoes transform into crisp, golden cakes with a runny egg on top. This is the quickest supper for using up half a bowl and feeding two hungry people. The egg yolk runs into the warm potatoes like sauce.

Serves 2. 20 minutes, 18 at the stove.

About 280 calories a serving, 9 g protein, 27 g carbohydrate, 16 g fat. From USDA figures for 100% of the ingredients; amounts are the recipe's.

You need about 2 cups mashed potatoes, 2 tablespoons butter, 2 eggs, to taste salt, to taste pepper.

1. Heat 1 tablespoon of butter in a large skillet over medium-high heat until it foams. While the butter melts, divide the mashed potatoes into 2 portions and shape each into a flat cake about 3 inches wide. When the foam subsides, lay both cakes in the pan.2 min
2. Cook without moving them for 4 minutes until the bottoms turn golden and crisp. Flip each cake gently and cook the other side for 3 minutes until it colors. Press down lightly as they cook to help them crisp.7 min
3. Push the cakes to the side of the pan and add the remaining 1 tablespoon of butter to the empty space. Crack 1 egg into the butter on each side, season with a pinch of salt and pepper, and cook for 2 to 3 minutes until the whites set but the yolks stay runny. Slide one cake onto each plate with an egg on top and serve right away.

Note Swap the eggs for a fried onion if you prefer. Leftovers keep in the fridge for three days and reheat in a skillet with a splash of water. Serve with a green salad or sautéed greens on the side to stretch the meal.

Fried potato cakes with a runny egg on top turn leftover mashed potatoes into dinner in twenty minutes. The crisp exterior and soft centre need nothing but salt and pepper and a squeeze of lemon.

Serves 2. 25 minutes, 20 at the stove.

About 610 calories a serving, 13 g protein, 61 g carbohydrate, 36 g fat. From USDA figures for 100% of the ingredients; amounts are the recipe's.

You need 2 cups [500 g] mashed potatoes, 3 tablespoons butter, to taste salt, to taste pepper, 3 tablespoons flour, 2 eggs, 2 tablespoons oil.

1. Mix 2 cups mashed potatoes with 3 tablespoons flour, half a teaspoon of salt, and a quarter teaspoon of pepper until combined. Divide into 4 equal portions and shape each into a cake about an inch thick.
2. Heat 2 tablespoons oil and 1 tablespoon butter in a large skillet over medium-high heat until the butter foams. Set 4 potato cakes into the pan without moving them until they are golden and crisp on the bottom, about 4 minutes.4 min
3. Flip each cake and cook the second side until golden, about 4 minutes. While they finish, crack 2 eggs into a small bowl.4 min
4. Push the potato cakes to the side of the pan. Add the remaining 2 tablespoons butter to the empty space and crack both eggs into it. Cook until the whites set but the yolks stay runny, about 3 minutes, shaking the pan to cook the edges of the whites.3 min
5. Place 2 potato cakes on each plate and top each with one fried egg. Taste and adjust salt and pepper.

Note Swap in 2 sliced scallions or chives stirred into the potato mixture for depth. Leftover potato cakes keep in the fridge for 3 days and reheat in a toaster oven at 400°F [200°C] until warm. Serve with a green salad or steamed greens on the side, or a spoonful of sour cream on each cake.

A few spoonfuls of leftover mashed potatoes become tender fritters, bound with egg and fried until golden. They are the vehicle for a fried egg on top and the quickest dinner when the pantry is almost bare.

Serves 2. 15 minutes, 12 at the stove.

About 270 calories a serving, 10 g protein, 12 g carbohydrate, 20 g fat. From USDA figures for 75% of the ingredients; amounts are the recipe's.

You need a few spoonfuls mashed potatoes, 3 eggs, 2 tablespoons flour, to taste salt, to taste pepper, 2 tablespoons oil.

1. Stir 1 egg into the mashed potatoes along with 2 tablespoons flour, a pinch of salt, and a crack of pepper until combined.
2. Warm 2 tablespoons oil in a skillet over medium-high heat until it shimmers. Shape the potato mixture into 2 rough cakes and slide them into the pan, flattening gently with a spatula. Fry for 3 to 4 minutes until the bottoms are golden and crisp, then flip and cook the other side for another 2 to 3 minutes until set throughout.7 min
3. Push the fritters to the side of the skillet. Crack the remaining 2 eggs into the empty space, season lightly, and fry in the hot oil until the whites set and the yolks reach your preferred doneness, about 3 minutes for soft yolks.3 min

Note Use grated cheese or a handful of chopped herbs mixed into the potato mixture if you have them. The fritters keep, chilled, for two days and reheat in a hot skillet. Serve with hot sauce, mustard, or a simple green salad on the side.