Cook the gnocchi according to package instructions. Drain completely. In a large skillet, heat olive oil over medium-high heat. Add the gnocchi in a single layer and cook, undisturbed, until golden and crisp, about 3-4 minutes. Turn the gnocchi and cook, turning occasionally, until golden and crisp, about 3 more minutes. Remove from the heat and stir in 1/4 to 1/3 cup of the pesto. You might have leftover pesto. Serve warm and garnish with Parmesan cheese, if desired.