2 medium sweet potatoes, skins on, quartered
1 large tomato, quartered
2 small red bell peppers, halved, seeds removed
2 packages active dry yeast
5-6 cups bread flour
2 teaspoons salt
2 tablespoons sugar
1 egg, beaten
1 cup warm water (should feel like a baby’s bathwater)
5 tablespoons extra-virgin olive oil, divided, plus more for greasing the bowl and dough
Preheat the oven to 400 degrees. Place the vegetables on a sheet pan, drizzle with one tablespoon of olive oil, and toss to coat. Roast the vegetables at 400 degrees for 20 minutes, until tender. Cool until they can be handled. Remove the skins from the potatoes and peppers (they should peel right off) and place the potatoes, peppers, and tomatoes in a small bowl or food processor. Add 2 tablespoons of olive oil. Puree with a hand blender or in the processor until smooth. Set aside.
In a large bowl, combine the yeast, sugar, salt, and 3 1/2 cups of bread flour. Add the vegetable puree and beaten egg and mix thoroughly. Pour in the warm water and 2 tablespoons of olive oil. Mix until it becomes a soft, sticky dough. Turn out onto a lightly floured surface and knead, adding the remaining bread flour, 1/2 a cup at a time, just until you have a soft dough that is smooth, elastic, and only slightly tacky to the touch.
Use a little olive oil to grease the inside of a large bowl, then place the dough in the bowl and rub about a teaspoon of oil over the top of the dough. Cover loosely with a clean towel and allow to rise in a warm place for 40-60 minutes, until doubled in size. Turn out onto a lightly floured surface and punch down, then divide in half. Grease two loaf pans. Put one piece of dough in each pan, cover with a clean towel, and allow to rise again until doubled in size.
Bake the loaves at 375 degrees for 20-30 minutes, until golden brown. They should sound vaguely hollow when tapped. Let cool in the pans for 20 minutes, then turn out and allow to cool upside-down for another 20-30 minutes to prevent the bottom crust from getting soggy.