Combine sundried tomato and pesto in small bowl. Refrigerate until later.
In large mixing bowl combine potatoes, flour, salt and egg. Mix until combined. Knead until mixture comes together into dough. Divide into 4 parts. Roll each part into log 1/2 inch wide. Cut into bite-size portions. Make an thumbprint in each portion. Cook in batches in boiling water until each dumpling floats to top. Remove with slotted spoon.
In large skillet over medium high heat, saute spinach in olive oil until wilted. Season to taste with salt. Stir in alfredo sauce and heat until hot. Remove from heat and stir in parmesan cheese.
To serve, spoon over potato gnocchi. Drizzle with pesto.