Mexican Chorizo and Corn Chowder



1 Tbsp olive oil
12 oz. pork or beef chorizo, casing removed
1 large onion, chopped
1 red bell pepper, diced
1 poblano pepper, diced
3 cloves garlic, minced
1/3 cup flour
1 tsp salt, plus more to taste
1/2 tsp freshly-ground black pepper, plus more to taste
1 tsp ground cumin
8 cups chicken broth
4 cups starchy potatoes (Russet or Yukon Gold), peeled and cut into 1/2-inch cubes
1 lb frozen corn kernels
1/2 cup Mexican crema or sour cream
1 cup Queso Fresco, crumbled
1/2 cup fresh chopped cilantro, for serving