Heat the olive oil in a large heavy pot over medium heat. Cook the leeks, celery, garlic, and thyme sprigs until browned (about 5-10 minutes).
Deglaze the pan with cooking wine making sure to scrape the caramelization from the bottom of the pot.
Stir in the chopped chard and potatoes and cook for about 5 minutes more.
Add the vegetable stock and bring to a boil. Reduce the heat to simmer and then add the pasta shells, green beans and peas.
Simmer uncovered for 10-12 minutes, or until the pasta is al dente and the vegetables are cooked.
While the soup is simmering, prepare the pistou.
In a food processor, purée the parsley, spinach, garlic, olive oil, salt (and gruyère/nutritional yeast if using).
Stop the machine and scrape down the sides to ensure everything purées evenly. Set aside.
Remove the thyme sprigs from the soup and stir in the lima beans.
Remove from heat, portion the soup into bowls and top each with a good dollop of pistou.
Serve with toasted baguette slices brushed with olive oil.
