Icelandic Vegetable and Oat Soup Recipe

Name: Icelandic Vegetable and Oat Soup Recipe
Prep time: 25 min
Cook time: 2 h
Total time: 2 h 25 min
Cuisine: European
Ingredients: 1/4 cup extra-virgin olive oil (plus more for garnish); 1 small yellow onion (finely chopped); 1 medium leek (trimmed and thinly sliced); 3 to 4 garlic cloves (minced); kosher salt; Freshly ground black pepper; 10 cremini mushrooms (thinly sliced); 4 medium carrots (cut into 1/4-inch slices); 8 cups water or low-sodium vegetable broth; 2 medium Yukon Gold potato (small dice); 2 cups cauliflower florets; 1 medium dried bay leaf; 1/4 cup old-fashioned rolled oats; 1 cup finely chopped kale (optional); Maldon sea salt or other flaky sea salt (for garnish)