Heat a large Dutch oven over medium-high heat.

Add olive oil and swirl to coat the pan.

Sprinkle chicken with 1/4 teaspoon salt.

Add chicken to the pan and cook for 5 minutes, or until browned, stirring occasionally.

Remove the chicken from the pan and set aside.

Add red onion, celery, carrot, rosemary, and thyme to the pan.

Cook for 7 minutes, or until the vegetables are tender.

Add 4 cups of chicken stock, scraping the pan to loosen any browned bits.

Bring the mixture to a boil, then reduce the heat and simmer for 8 minutes.

Add gnocchi to the pan and cook for 3 minutes, or until the gnocchi float to the surface.

In a bowl, combine the remaining 1 cup of chicken stock and flour, stirring with a whisk.

Slowly add the stock mixture to the pan, stirring constantly with a whisk to avoid lumps.

Stir in the cooked chicken and frozen green peas.

Cook for 5 minutes, or until the peas are heated through and the soup has thickened slightly.

Stir in the remaining 1/4 teaspoon salt and black pepper to taste.

Serve hot.