White Bean Chili with Winter Vegetables

Name: White Bean Chili with Winter Vegetables
Ingredients: 1 tablespoon olive oil; 2 leeks, white and 1' of pale-green part, diced; 4 garlic cloves, finely chopped; 2 large carrots, peeled, cut into 1/4' cubes; 2 large or 3 medium parsnips, peeled, halved lengthwise if large (remove woody center, if needed), cut into 1/4' cubes; 1–1 1/2 tablespoons ground ancho chiles; 1 teaspoon ground cumin; 1 /2 teaspoon dried oregano; 2 teaspoons kosher salt plus more for seasoning; 1 1/4 cups dried cannellini (white kidney) beans, soaked overnight (to yield about 3 cups) or two 15-oz. cans cannellini beans, rinsed; Cilantro leaves (optional); 1 ripe avocado, peeled, chopped