It's honestly going to be tough going getting enough protein from a vegetarian or vegan diet.
Protein consists of amino acids. There are twenty or so amino acids, depending on who you ask. Exactly 8 of those amino acids are referred to as Essential Amino Acids, that is they are essential for our bodies, and we will not develop muscle without them.
Meats, eggs, and various whey proteins are advertised as being 'complete proteins', which means they contain all of the necessary amino acids to promote growth.
Many vegetables are often labeled as have protein in them, or having a 'high protein content'. While this is not untrue, it is not exactly true either. Many vegetables contain a variety of amino acids. The only vegetable known to be a complete protein source is soy, of which the benefits are, at very best, debatable.
So, to obtain a complete spectrum of protein from vegetables, the key is variety and quantity. Remember those two key words and you should be able to bulk up at a reasonable rate.