I like them savory, not sweet.
They pair well with fresh herbs, flavorful herby sauces and pastes (chutney/chimichurri/charmoula/salsa verde/harissa/indian chutney), or other strongly flavored condiments and ingredients.
Also with a foil of something creamy and/or tart - like yogurt, sour cream, cheese, etc.
Steam in the microwave or pressure cooker, then slice into rounds or mash. Top with butter, yogurt or sour cream and fresh herbs or one of the strongly flavored condiments above. I don’t love the fibrousness of some varieties - a ricer helps with that.
Fries / oven fries / roasted in cubes are always good too. Sweet potatoes don’t get very crisp on their own, so if you want you can lightly coat with seasoned flour or `cornstarch or similar (Ottolenghi uses cornmeal / polenta but I don’t like that grainy mouthfeel in the end product).
You can use them in many (but not all) places that call for potatoes - eg Indian potato sautes and curries, patties, stuffed breads (samosa, paratha, naan), chaat, etc.
There are some places I don’t think they work as a potato substitute because of the sweetness and flavor - shepherds pie topping, gratin, and similar.
They can also be used in places you might use butternut squash. A fall fattoush is one idea.
