Ancho Chile Soup with Avocado, Crema, and Chile Pasilla (Sopa de Chile Ancho)

Ingredients

• 3 dried ancho chiles
• 4 medium plum tomatoes
• 2 cloves garlic
• 1 small white onion
• 1⁄2 cup canola oil
• 8 small dried pasilla chiles
• 8 cups chicken stock
• Kosher salt and freshly ground black pepper, to taste
• 1 cup queso fresco, crumbled
• 8 sprigs cilantro, finely chopped
• 1⁄2 cup crema or sour cream
• 1 avocado, very thinly sliced
• Fried tortilla strips, for garnish