Preparation

1. Heat oil in a large soup pot over medium-high heat. Add the shallot and sauté until translucent, about 3 minutes. Add the mushrooms and sauté until they soften; about 5 minutes. Add the farro and stir for about 30 seconds until toasted a bit. Add the vegetable broth, bring to a boil; then reduce heat to low, cover and simmer 30 minutes. (to reduce the cooking time, soak the farro overnight, then drain, in this case, it will only need to simmer for 10 minutes).
2. Heat a large frying pan over medium-high heat. Add the walnuts to the hot, dry pan, only toasting as many walnuts as fit in the pan in a single layer. Cook, watching constantly and stirring frequently until the walnuts start to brown and they smell toasted about 5 minutes. Once cool enough to touch, roughly chop walnuts.
3. When the farro is cooked, drain off any excess liquid. Stir in toasted walnuts. Add salt and pepper to taste.