Could kick up the protein in your vegetable soup with chickpeas, lentils, wild rice, chia/hemp seeds (if you're into that)..

Some others could be spinach, sweet potatoes, and asparagus. Possibly quinoa on top.

Nutritional yeast is popular. I use it sometimes but can't say I love it just yet. Haven't cooked with it much but it seems to be used frequently in some recipes.

Lots of good options!

https://www.healthline.com/nutrition/protein-for-vegans-vegetarians