Heat the olive oil in a soup pot over medium high heat. Add the chopped onions and saute, stirring occasionally, until golden, about 15 minutes.
2 Tablespoons olive oil, 2 medium yellow onions
Add the celery, carrots, celery root, vegetable broth, split peas, thyme sprig, and 2 Tablespoons of the dill. Bring to a boil. Stir to combine.
2 medium celery stalks, 2 medium carrots, ¼ medium celery root, 6 cups vegetable broth, 2 cups dried green split peas, 1 sprig fresh thyme, 4 Tablespoons chopped fresh dill, divided
Reduce heat to medium low, cover, and simmer for 45 minutes to 1 hour, until peas are soft and soup is fragrant.
Season the with soup with salt and pepper to your liking.
salt and pepper
Meanwhile, saute the sliced onions in a skillet over medium high heat, stirring often, until blackened and crispy, about 15 minutes. Remove from skillet and set aside for topping.
2 medium yellow onions
Serve the soup topped with the blackened onions and the remaining fresh dill.
4 Tablespoons chopped fresh dill, divided