Slice the chicken breasts horizontally to create thinner cutlets, about ¼ inch thick. Season with salt and pepper. Layer prosciutto and sage on each cutlet, securing with toothpicks.

Heat olive oil in a skillet over medium heat. Add sage leaves and fry until crispy, about 1-2 minutes. Remove and drain on paper towel.

Increase heat to medium-high and cook chicken, prosciutto-side down for 3-4 minutes until crispy. Flip and cook for another 2-3 minutes until cooked through.

Lower heat and deglaze with white wine, scraping up browned bits. Simmer and reduce wine by half, about 3 minutes. Add chicken stock and simmer until sauce thickens slightly, around 2-3 minutes.

Remove skillet from heat and stir in cold butter until melted and glossy. Adjust seasoning with salt and pepper.

Remove toothpicks from chicken, plate and drizzle with sauce, garnishing with fried sage.