In the pantheon of using-up-leftovers dishes, hash is at or near the top, alongside fried rice and the frittata. Do I need to even state the obvious, that you shouldn't limit hash to breakfast or brunch? I didn't think so.
It's flexible, too: Saute whatever allium you like, add cubed potatoes or sweet potatoes, fry them all up, fold in leftover vegetables and/or meat, top with an egg if you like, serve, eat.
This version by vegan writer and YouTube star Jenné Claiborne, author of "Sweet Potato Soul," is a little more intentional, but it's super-quick to make. In her e-book "5-Ingredient Vegan," she takes a bit of a departure from the typical hash recipe: Rather than pan-frying cubes of sweet potatoes until they're crisp, she has you thinly slice the root vegetable, layer the medallions in a skillet (alternating with onions and bell peppers) and cook it covered. The sweet potatoes brown on the bottom while they lightly steam. You fold in chopped collard greens for more nutrition and texture, and the whole thing is ready in a matter of minutes.
Claiborne serves the hash with patties she makes from crumbled tempeh, but store-bought tempeh "bacon" would be good, too. If you're not into either, there's nothing stopping you from cracking in an egg, or frying it up separately and serving it on top, or serving the hash as a side. If the idea of the tempeh patties does call to you, consider it another reason to buy Claiborne's book.