Curry Spiced Cauliflower Parsnip Soup
1 tablespoon extra virgin olive oil1 small or 1/2 large yellow onion, chopped1 parsnip, peeled and chopped2 ribs celery, chopped1/2 head cauliflower, chopped1 apple, peeled and chopped4 cups chicken or vegetable stock1/2 teaspoon kosher salt, or more to taste1/4 teaspoon...