Pork Sandwich with Romesco Sauce | Food Stuff

Ingredients

• 1 dry ancho chili
• 2 cups packed arugula
• 4 (6-inch long) crusty rolls, such as ciabatta
• 4 large garlic cloves, peeled and smashed
• 1/3 cup toasted slivered almonds or toasted skinned hazelnuts
• Kosher salt and freshly ground black pepper
• 1/4 cup mayonnaise (optional)
• 2 tablespoons olive oil
• 3/4 cup drained canned or jarred piquillo peppers
• 3/4 cup drained and crushed canned plum tomatoes
• 1 (1 1/2 -pound) pork tenderloin, cut crosswise into 1 inch-thick medallions
• 2 tablespoons sherry vinegar
• 1 1/2 teaspoons smoked paprika
• 3 strips thick-cut bacon, chopped
• 1 slice hearty white bread, torn into pieces
• 1 medium yellow onion, peeled and thinly sliced (about 1 cup)