How does a vegetarian combine incomplete proteins to get all nine amino acids?

Vegetarians can combine incomplete proteins to ensure they receive all nine essential amino acids by pairing different plant-based foods. For example, combining legumes (like beans or lentils) with grains (such as rice or quinoa) creates a complete protein profile, as legumes are typically low in methionine but high in lysine, while grains provide the opposite. Other combinations include nuts or seeds with legumes or dairy with grains. By consuming a variety of these combinations throughout the day, vegetarians can meet their amino acid requirements effectively.