Here is the recipe for my absolutely favourite soup. JB put a call out for fav vegetarian recipes, and this is mine! I got this recipe from a wonderful greek vegetarian cookbook, but have modified it slightly to be more of a meal (added lentils).
the juice of 4-5 lemons
2 med celeriac
1/3c olive oil
3 cloves garlic
2 med carrots
4 med potatoes
5 (plum) tomatoes
~1.5 cup dry red lentils (more if you like)
black olives (we usually put maybe 10-20, depends on your taste - this is where the salt is coming from, so use your judgement)
Pour about 1T oil in pot and heat. Add celeriac cubes and "steam" the celeriac in oil for 4 min. [This step seems weird to me, but I always do it, soup always turns out marvelous]. Add garlic, carrots, potatoes, olives and tomatoes. Cover with water and bring to a boil, then reduce heat and simmer 30 min.
Add very thoroughly washed dry red lentils (no need to pre-soak) [VERY WASHED - rinse and change water like 5+ times, or you'll end up with crazy starch problems], simmer and additional 15 min.
Add lemon juice. Beat egg in a separate bowl, and drizzle slowly into the soup as you're stirring. This is the magic - the egg makes the soup creamy and delicious (and adds a wee bit more protein to boot!), without any butter or cream. The lemon and egg are what make this an avgolomeno. Add the rest of the olive oil (greeks are not shy with the oil, eh?), and serve! Goes well served with bread, if you're of the type to eat bread.
YUM! And before this - what on earth would I have done with celeriac? Passed it by at the supermarket is what! (Truth be told, they are dirty and a bit scary looking.) Now celeriac and I are good friends.