Potato Croquetas with Saffron Alioli

INGREDIENTS

• 3/4 cup all-purpose flour
• 1/2 teaspoon salt
• 1 pound large boiling potatoes (about 2)
• 3/4 cup fine dry bread crumbs
• 1 tablespoon finely chopped fresh chives
• 1 tablespoon chopped fresh flat-leaf parsley
• About 4 cups olive oil (not extra-virgin) for frying
• 1/4 teaspoon chopped fresh tarragon
• 2 tablespoons unsalted butter, softened
• Accompaniment:
• 3 large eggs
• 1/8 teaspoon black pepper