Spiced Catfish With Avocado

Name: Spiced Catfish With Avocado
Ingredients: 1 tablespoon coriander seeds; 1 tablespoon cumin seeds; 1 tablespoon dried thyme; 1 tablespoon dried oregano; 2 teaspoons chipotle chile powder; 2 teaspoons ancho chile powder; 2 teaspoons salt; 1 teaspoon sugar; 1 teaspoon ground mace; 1 teaspoon ground cinnamon; 1/2 teaspoon freshly grated nutmeg; 4 medium yellow onions, chopped; 4 garlic cloves; 2 tablespoons poppy seeds; 1/4 cup extra-virgin olive oil; 4 pounds catfish fillets, cut into 1-inch pieces; 2 cups water; 2 medium red onions, finely diced; 2/3 cup fresh lime juice; Kosher salt; 4 ripe Hass avocados, cut into 1-inch dice; Basmati rice, for serving