Toast cumin seeds in heavy small saucepan over medium heat until beginning to darken in color, stirring often, about 3 minutes. Cool 10 minutes. Enclose in plastic bag and crush with hammer or mallet. Heat oil in heavy large saucepan over medium-high heat. Add onion, Anaheim chili, and garlic. Saute until onion is translucent, about 5 minutes. Add New Mexico chili, oregano, and cumin seeds. Stir 2 minutes longer. Add broth, hominy, tomatoes with juices, and tostadas caseras. Bring soup to boil; reduce heat to medium-low, cover, and simmer until dried chili is very soft and flavors blend, about 45 minutes. Season soup with salt and pepper, then lime juice to taste. (Can be made 1 day ahead. Chill uncovered until cold, then cover and keep chilled. Rewarm soup before serving.) Ladle soup into bowls. *Also known as a California chili; available at Latin American markets and many supermarkets. **Available at Latin American markets and some supermarkets.