Blanching is not what I'm referring to. Blanching is a very short time in boiling water, usually not enough to cook something, followed by a plunge in cold water, so if you stop there your food will also be cold. It is a pre cooking step, done either done to preserve color/texture (if I boil small chopped up leek before making "fondue de poireaux"), or to neutralize bitterness/sourness (if I make lemon slices confit in syrup).

What I'm referring to is following the cooking charts your might find in a culinary school textbook about vegetables, because you can absolutely cook any vegetable to steaming hot perfection in just salted boiling water, even broccoli or Brussels sprouts.