Both Kals Brand and Red Star Nutritional Yeast have excellent protein profiles, in particular Lysine

Kals: http://www.vitacost.com/Kal-Nutritional-Yeast-Flakes

In this brand, there's 918 mg of Lysine in three rounded tablespoons. There's also a lot of B vitamins. Since I became vegan, I use Red Star or Kals every day. I would have to estimate that I eat about 1/4 cup of it mixed into soups, sprinkled on salads, added to scramble, and also sprinkled on all vegetables. I love the stuff.

Red Star: http://truefoodsmarket.com/nutritional-yeast-large-flake-1-lb.html

You can make soup bases, dips, and sauces with nutritional yeast.

Here's a dip that I make frequently:

1/2 cup of Nutritional Yeast
1/2 to 1 teaspoon garlic granules
1/2 teaspoon more or less of iodized salt. I use the ancient mineral stuff.
1 tablespoon lemon juice
1/8 teaspoon dijon
1/2 cup raw cashews (bits and pieces are dry, but you can work with them if you soak them for a little while in water)
1/8 cup water

Process till smooth.

Spice it up more and add roasted red peppers and/or avocado. I water this down for a salad dressing or soup base. I make a sauce for veggies and thicken it with blended Northern white beans or arrow root. Sometimes I use beans in replacement of the cashews and omit the dijon. I also water down homemade hummus to use as dressings and sauces. Whatever I have around. You can add some (a couple drops) of liquid smoke to this dip, it is wonderful.