In a large skillet over medium heat, combine broth, heavy cream, and fresh thyme. Stir well and bring to a gentle simmer for about 5-10 minutes.

In a small bowl, create a cornstarch slurry by mixing cornstarch with cold water. After the sauce has thickened slightly, whisk in the cornstarch slurry and turn the heat up to medium-high, stirring continuously for 2-3 minutes until the sauce thickens.

Bring a large pot of salted water to a boil. Add gnocchi and cook until they float to the surface, about 2-4 minutes. Drain and set aside, retaining a bit of the pasta water.

Remove the thyme sprigs from the skillet and lower the heat. Gradually stir in grated Parmesan cheese until melted and fully incorporated into the creamy sauce. Fold in the drained gnocchi, mixing gently. If too thick, add a splash of reserved pasta water.

Plate the gnocchi into serving bowls, and finish with extra Parmesan, a sprinkle of salt, and freshly cracked black pepper to taste.