Combine the ancho chile powder, sugar, ground fennel, cumin, 1 teaspoon salt, and 1/4 teaspoon ground pepper in a small bowl. Sprinkle 1 side of the marlin with about 1 teaspoon of the spice mixture. Heat oil in a large saute pan and sear the fish, spice-side down, until golden brown. Turn the fish over and cook for 3 to 4 minutes. Brush with the barbecue sauce, turn over, and cook for 30 seconds. Turn over and brush with more of the sauce. Keep warm. In the center of each of 4 dinner plates, place 2 heaping tablespoons of Spicy Yellow Rice with Red Beans. Place a marlin fillet on top of the rice at an angle. On one side of the marlin fillet, at the base of the mound of rice, place a dollop of Avocado Puree.
Heat oil in a medium saucepan over medium-high heat. Add the onions and cook until soft. Add the garlic and cook 1 minute. Add the ancho, cumin, and cayenne and cook for 2 minutes. Add the rice and stir to coat each grain with the mixture. Add the water and saffron, and salt, to taste. Bring to a boil. Cover the pot, lower the heat, and cook for 12 to 15 minutes, until the water is absorbed and the rice is tender. Fold in the beans and green onions and re-season.
Place avocado and lime juice in a food processor and process until smooth. Add the honey and pulse 3 times. Add the cilantro and pulse until just combined but there are still some flecks. Season with salt and pepper, to taste.