1. Bring the water to a gentle simmer.
2. In a bowl, combine the Mousline instant mashed potato flakes and flour, then add the hot water and mix. Stir vigorously for 2 minutes, then add the egg, a pinch of salt, and pepper.
3. Knead the dough until it is no longer sticky.
4. Divide the dough into 4 portions and roll each into a log. If necessary, lightly flour your hands and work surface.
5. Cut the dough logs into small cubes about 1.5 cm long.
6. Bring a large pot of salted water to a boil and add the gnocchi. As soon as they float to the surface, drain them in a colander.
7. Wash the basil and peel the garlic.
8. Blend the olive oil with the garlic, walnuts, and basil, then season with salt and a squeeze of lemon juice: your pesto sauce is ready!
9. Toss the gnocchi with your homemade pesto sauce. Add a few halved cherry tomatoes and garnish with basil leaves.
