Blanching vs parboiling is chiefly a question of purpose: blanching briefly cooks vegetables for freezing, salads, or peeling, while parboiling partially cooks them before roasting, grilling, or baking.
Essential Concepts
Purpose matters more than timing; an ice bath is not always necessary.
Related post: Roast potatoes https://www.bbcgoodfood.com/recipes/ultimate-roast-potatoes
