These 5 plant-powered sources of protein are amazing!. 1. Tofu is not only rich in protein, but also has amino acids that are vital for tissue repair. 2. Soy milk has 7 grams of protein per serving, while the same portion of cow’s milk has 8 grams. 3. Lentils have double the protein of quinoa, and can be made into burgers!. 4. Just two tablespoons of chia seeds provide an impressive 6 grams of protein. 5. Peanut butter is not only packed with protein, but with healthy fats!