01 - Heat olive oil and butter in a large deep skillet or Dutch oven over medium heat until melted and shimmering.
02 - Add onions, carrots, and celery. Cook for 5–6 minutes, stirring occasionally, until vegetables begin to soften and onions turn translucent.
03 - Stir in minced garlic and cook for 30 seconds until fragrant, being careful not to burn.
04 - Sprinkle flour evenly over the vegetables. Stir constantly for 1–2 minutes to cook off raw flour taste and form a smooth roux.
05 - Gradually whisk in chicken broth and milk, stirring continuously to prevent lumps from forming.
06 - Add thyme, sage, salt, and pepper. Bring to a gentle simmer and cook for about 5 minutes until sauce noticeably thickens.
07 - Stir in uncooked gnocchi, shredded chicken, and frozen peas. Ensure gnocchi are fully submerged in the sauce.
08 - Cover and reduce heat to maintain a gentle simmer. Cook for 10–12 minutes, stirring occasionally, until gnocchi are tender and sauce is creamy.
09 - Remove from heat. Stir in grated Parmesan if using, allowing residual heat to melt the cheese.
10 - Sprinkle with chopped fresh parsley just before serving ladle portions into bowls.