Preheat the oven to 425°F. Line a baking sheet with parchment paper.
Add gnocchi and tomatoes to the prepared baking sheet. Drizzle with oil, salt, and pepper. Toss to combine evenly. Bake for 30 minutes, until gnocchi is golden and crisp at the edges.
Prepare the Garlic Parsley Mayo. Add all ingredients to a jar or container. Blend all together using an immersion blender. Refrigerate until ready to serve.
To plate the dish, place gnocchi with tomatoes in the center of an appetizer plate. Top with shredded beef. Sprinkle on the crispy onions. Dollop garlic parsley mayo and some fresh parsley leaves and serve.