Ingredients

• 3 ounce sourdough bread, crust removed, torn into small pieces (about 1 cup), divided
• 1 tablespoon plus 1/3 cup olive oil
• Kosher salt
• freshly ground pepper
• 1 small garlic clove
• 2 tablespoons red wine vinegar
• 1 teaspoon Dijon mustard
• 1 teaspoon sugar
• 1 head radicchio, leaves separated, torn if large
• 2 scallions, thinly sliced

Instructions

1. Preheat oven to 425°. Toss half of bread with 1 tablespoon oil on a rimmed baking sheet; season with salt and pepper. Bake, tossing once, until golden brown, 8-10 minutes.
2. Pulse garlic, vinegar, mustard, sugar, remaining bread, and 2 tablespoons water in a blender to combine; let sit 5 minutes to soften bread. With motor running, gradually add remaining 1/3 cup oil; blend until smooth (bread will blend into dressing, thickening and flavoring it, while retaining some texture), about 2 minutes; season with salt and pepper.
3. Toss radicchio, scallions, croutons, and dressing in a large bowl; season with salt and pepper.