For the sun-dried tomato cashew cream: Place the cashews in a large heat-proof glass jar or medium bowl and cover with boiling water. Soak until the cashews are softened, 25 to 30 minutes, or let cool and soak overnight in the fridge. (A longer soak creates a smoother blend.)
For the sheet pan: When ready to cook, preheat the oven to 375°F. Line a sheet pan with parchment paper.
In a large bowl, combine the gnocchi, eggplant, zucchini, cherry tomatoes, and garlic cloves. Add the oil, basil, oregano, salt, black pepper, and red pepper flakes (if using) and toss to coat evenly. Transfer to the prepared sheet pan and spread out in an even layer.
Bake until the vegetables are softened and slightly browned around the edges, 22 to 25 minutes. Set aside the roasted garlic cloves.
Finish the sun-dried tomato cashew cream: Drain the cashews in a colander and transfer them to a blender or food processor, along with the garlic, sun-dried tomatoes, salt, and ¾ cup water. Blend on high speed until smooth, about 60 seconds. Add more water if needed for a pourable consistency. If needed, season with more salt.
To serve, spread the cashew cream onto the surface of four plates. Top with the gnocchi and vegetables.
