You may have seen green split pea soup before, but I love the color the yellow split peas give my version. Turmeric also gives it a golden hue and lends an earthy flavor. For added creaminess, I like to dollop a little smoky sour cream on top.
Heat the oil in a Dutch oven over medium-high heat. Add the onion, garlic, carrots, celery and turmeric and cook until the vegetables are tender, about 5 minutes. Add the peas, vegetable broth, thyme and 1/2 teaspoon each salt and pepper.
Bring to a boil; cover, reduce the heat to low and simmer until the peas are tender and the soup is thickened, 40 to 45 minutes. Stir in 1 to 2 cups water at the end of cooking if the soup is too thick.
Meanwhile, stir together the sour cream, paprika and 1/4 teaspoon each salt and pepper. Spoon the soup into serving bowls and top with the sour cream. Garnish with thyme, if desired.