Cook diced potatoes until tender in a small saucepan or microwave.

Drain potatoes, reserving the potato water.

Mash potatoes with a fork.

Add water to the potato water to make 3/4 cup.

Place mashed potato, potato water, eggs, butter, lemon peel, sugar, salt, and bread flour in the bread machine pan.

Add active dry yeast last.

Select the dough cycle and press start.

Monitor the dough consistency, adding flour (1 tbsp at a time) if too sticky or water (1 tbsp at a time) if too dry.

When the bread machine signals, add raisins and allow the cycle to finish.

Prepare two bread pans by greasing them and sprinkling with cornmeal.

Divide the dough between the pans and let it rise for 15-20 minutes.

Cut three slits into the top of each loaf and brush with beaten egg.

Preheat oven to 350°F (175°C).

Bake for 30-35 minutes, covering with foil after 15 minutes to prevent burning.

Check for doneness with a cooking thermometer (internal temperature 200-210°F).