Preheat the oven to 425 °F. Lay out one or two sheet pans (see note 2).
To a large bowl, add the gnocchi, broccoli florets, butternut squash, red onion, olive oil, thyme, sea salt, onion powder and black pepper. Toss to combine until the vegetables and gnocchi are evenly coated in oil and seasoning.
Divide the mixture between the two sheet pans, spreading it out in a single layer for even roasting.
Roast for about 25 minutes, stirring once halfway and switching the position of the pans for even roasting. It's done when the butternut squash is fork tender.
While the vegetables are roasting, prepare the brown butter sauce. Heat a light-bottomed medium-sized sauce pan over medium heat (no hotter, you don't want to burn the butter and a light-bottomed pan will help you see the colour). Melt the butter. Once the butter is bubbling, add the minced garlic and cook for about a minute, stirring frequently with a wooden spoon.
Add the sliced sage to the butter and continue to stir frequently. Watch the butter carefully (do not walk away!). The brown butter is done once you see the milk solids turning a golden/brown colour and you smell a nutty aroma. Once it's done, carefully pour the brown butter to a heat-safe bowl so that it stops cooking and doesn't burn.
When the gnocchi is done roasting, carefully transfer it all to one sheet pan, then drizzle the sauce over top. Toss until the gnocchi mixture is evenly coated in sauce, season with additional salt and pepper, if desired, and serve. Store any leftovers in a sealed container in the refrigerator and eat within 4 days.
Be sure to cut the butternut squash fairly small (1/2-inch dice), to ensure it cooks fully within the same time as the other vegetables.
You can technically use just one sheet pan if you're using a very large one (13"x18"). Just note that the vegetables will be less caramelized because they will steam each other from being closer together (less air flow between them). If you make it on one pan, you can skip using the large bowl to add the oil and seasonings and just add these to the gnocchi and veggies right on the pan.