Choose your substitute based on the dish goal: roasting browning, creamy mashing, or baked casseroles.
Swap by the listed ratio; if the substitute is sweeter (sweet potato), reduce the amount and adjust seasoning.
Match texture prep: cut root vegetables smaller for faster tenderness and more even caramelization.
If your substitute is stronger in aroma (celeriac), balance with herbs, butter, or a splash of acid (lemon or vinegar).
Taste at the end and fine-tune: add salt for depth, black pepper for bite, and a pinch of nutmeg for “parsnip-like” warmth.