Preheat oven to 350 F. Spread walnuts onto a small baking tray and toast for about 10 minutes. Remove from oven, let cool, and roughly chop. In the meantime, proceed with the rest of the recipe.
Preheat a large pan over medium heat. Saute shallots in olive oil with a pinch of salt until lightly browned, about 5 minutes. Add garlic, tarragon and black pepper and saute another minute.
Add nutritional yeast and stir with a wooden spatula to toast for about 1 minute. Add white wine and to deglaze the pan. Let cook for about 3 minutes.
Add vegetable broth and bring to a boil. Add the greens and cook down for about 5 minutes. Add the lentils and toss to heat through. Serve topped with walnuts!