Preheat your oven to 450 degrees F.
Prep all of your veggies as directed above.
Line a large sheet pan with parchment paper. Add on the gnocchi, tomatoes, zucchini, garlic, onion, and sausage (if using).
Drizzle everything with the olive oil, then season with salt, smoked paprika, Italian seasoning, black pepper, and red pepper flakes (if using). Mix well, until everything is evenly coated. (Alternatively, you can mix this all in a bowl if you'd like, then pour onto your sheet pan.)
When you're done mixing, spread everything out so that it's all in one even layer.
Bake the sheet pan in the oven for 20 minutes, then take out and stir. Put the sheet pan back in the oven for another 20-25 minutes, or until the veggies are starting to brown in places.
For extra crisp, you can broil the sheet pan for 2-3 minutes on high, if desired.
When done, remove from the oven and garnish with feta or parmesan cheese, fresh herbs, and any other toppings you'd like.
Serve straight from the sheet pan, and enjoy!