2 Tbsp. olive oil
2 medium potatoes, peeled and cut into 1/4-in. dice
1 medium Spanish or yellow onion, trimmed, peeled and cut into 1/4-in. dice
1 leek, trimmed to 5 - 6 in., quartered lengthwise and cut into 1/4-in. dice
6 - 8 large carrots peeled, trimmed, quartered lengthwise and cut into 1/4-in. dice
2 tsp. ground coriander, toasted
1 1/2 qts. chicken broth
cilantro and sour cream for garnish