Peel and chop the purple sweet potato into small chunks. Place in a saucepan with water, bring to a boil, then reduce heat and simmer until soft. Cool and puree until smooth.
Measure 1 1/2 cups of the potato liquid/puree mixture. Sprinkle yeast and sugar over the top and let sit for 5 minutes until foamy.
Add salt and a small amount of flour. Stir, then gradually add more flour until a soft dough forms. Knead by hand until the dough becomes smooth and no longer sticky.
Place dough in an oiled bowl, cover, and let rise in a warm place for about 1 hour, or until doubled in size.
Punch down the dough, then shape into a loaf. Place on a baking sheet.Brush with egg wash and let rise again for 20 minutes while the oven preheats to 400°F.Bake for 18-20 minutes until the top is golden and the loaf sounds hollow when tapped.
Assemble the Crostini
Slice the bread into ½-inch slices. Top each slice with: 1 tablespoon pea pesto, a piece of crispy bacon or parmesan, an edible flowerArrange on a serving platter and serve immediately.