Preheat the oven to 400°F (200°C).
Place the drained sun-dried tomatoes on paper towels and press to remove excess oil, then dice them.
Cook the gnocchi according to package directions (about 3–5 minutes), drain and set aside.
Heat 1 teaspoon olive oil in a large oven-safe skillet over medium-low heat. Add the diced sun-dried tomatoes and minced garlic with a pinch of kosher salt and pepper, and cook 2–3 minutes until softened.
In a shaker cup or jar, combine 1 1/2 cups stock and 1 tablespoon flour and shake until smooth. Pour the slurry into the skillet while stirring constantly; cook a few minutes as it warms and slightly thickens.
Stir in 2/3 cup cream and 1/2 cup grated Parmesan until combined. Add the cooked gnocchi and stir to coat evenly in the sauce.
Top the gnocchi mixture with the torn or sliced fresh mozzarella. Transfer the skillet to the preheated oven and bake 20–25 minutes until bubbly and the cheese is melted.
Remove from oven and top with fresh basil, extra Parmesan, and crushed red pepper flakes to taste before serving.
