"Do you have the vegetable recipes?"
Translation:Est-ce que tu as les recettes de légumes ?
Which one is actually better? "Est-ce que tu as ..." ou "As-tu ..."? I find the last form way easier to remember than the first one. But if it sounds weird in day to day French then I'd better learn the "Est-ce que" way... But if not, I will be grateful. Duolingo likes both answers by the way.
Not incorrect, grammatically speaking, but with a slightly different meaning:
des recettes de légumes = recipes involving vegetables (no other major ingredient)
des recettes aux légumes = recipes with vegetables added, as secondary ingredients, the primary ingredient probably being a protein of some kind (meat, fish).
"du" is singular so it would not work with plural "légumes" anyway.
For expressions using the format "noun of noun", the article is dropped:
une feuille de papier (sheet of paper)
une recette de légumes (vegetable recipe)
un mur de pierres (stone wall or wall made of stones)