Ingredients

• 2 large eggs
• 1 1/2 cups breadcrumbs or panko (Japanese breadcrumbs)
• 3/4 cup finely grated Parmesan (about 2 ounces)
• 5 tablespoons olive oil, divided, plus more for brushing
• 3 1/2 teaspoons dried oregano, divided
• 3/4 teaspoon kosher salt, divided
• 3/4 teaspoon freshly ground black pepper, divided
• 4 (6-ounce) chicken cutlets, pounded 1/2" thick
• 6 ounces coarsely grated mozzarella (about 1 cup)
• 1/2 medium onion, chopped
• 2 garlic cloves, pressed or finely chopped
• 1 (24-ounce) jar marinara sauce
• 1/4 teaspoon crushed red pepper flakes (optional)
• 1/4 cup (packed) basil leaves, torn if large, plus more for serving

Instructions

1. Arrange racks in top and bottom of oven and place a rimmed baking sheet on bottom rack; preheat to 450°F.
2. Beat eggs in a large shallow bowl. Using a fork or your fingertips, mix breadcrumbs, Parmesan, 3 Tbsp. oil, 3 tsp. oregano, 1/2 tsp. salt, and 1/2 tsp. pepper in another large shallow bowl or plate.
3. Working with 1 cutlet at a time, dip in egg, allowing excess to drip back into bowl. Dredge in breadcrumb mixture, shaking off excess, then pressing to adhere. Transfer chicken to a baking sheet.
4. Carefully remove preheated baking sheet from oven and generously brush with oil. Transfer chicken to baking sheet and return to bottom rack. Roast 6 minutes, then carefully flip (use a spatula to scrape under cutlets) and sprinkle with mozzarella. Place baking sheet on top rack and continue to roast until juices run clear, mozzarella is melted, and an instant-read thermometer inserted into the center of cutlet registers 165°F, about 4 minutes more.
5. Meanwhile, heat remaining 2 Tbsp. oil in a large skillet over medium-high. Cook onion, stirring, until softened, 3–4 minutes. Add garlic and cook until fragrant, about 1 minute more. Add marinara sauce, red pepper flakes (if using), 1/4 cup basil, and remaining 1/2 tsp. oregano, 1/4 tsp. salt, and 1/4 tsp. pepper. Cook, stirring, until sauce starts to bubble. Reduce heat to medium and simmer until chicken is ready, stirring occasionally, at least 5 minutes.
6. Divide sauce among 4 plates. Top with chicken and torn basil.