This vegetarian Onion Fennel and Mushroom soup gets much of its savoriness from the variety of mushrooms in it. Keep this soup interesting by switching up the combination each time you make it.

Ingredients
5 tbsp. olive oil
3 large yellow onions, thinly sliced
1 bulb fennel, halved and thinly sliced lengthwise, fronds reserved
2 cloves garlic, minced
8 cups mushroom or beef stock
1 lb. mixed mushrooms, such as cremini, shiitake, or portobello, roughly chopped
1⁄4 cup dry white wine
Kosher salt and freshly ground black pepper

Instructions
In a large saucepan, heat 4 tablespoons olive oil over medium-high. Add the onions and fennel and cook, stirring, until soft and caramelized, about 1 hour. Add the garlic and cook, stirring, until fragrant, 2 minutes. Pour in the stock and bring to a simmer over medium heat.
Meanwhile, in a 12-inch skillet, heat the remaining 1 tablespoon olive oil over medium-high. Add the mushrooms and cook, stirring, until golden, about 5 minutes. Add the wine and cook until slightly reduced, about 5 minutes. Scrape the mushrooms and wine into the soup and cook, stirring, to marry flavors, about 5 minutes. Season the soup with salt and pepper, ladle into bowls, and garnish with the reserved fennel fronds.