Choose your substitute based on the dish type and desired flavor match. Use parsnip or celery root for cooked dishes, jicama for raw preparations, and tamarind paste only when body and tang are the goal.
Prepare the substitute as directed: peel and cut root vegetables into the same size and shape as burdock root called for in the recipe. For tamarind paste, measure carefully and dilute with water or broth if needed.
Apply the substitution ratio carefully. Start with the stated amount (1:1.1 for parsnip, 1:1 for carrot and celery root and jicama, 1:2 for tamarind paste) and adjust to taste after cooking.
Taste and adjust seasoning. Carrot and parsnip add sweetness, so reduce sugar or mirin slightly. Tamarind adds acidity, so reduce other sour components by about half.