Preheat the oven 400 degrees. Lightly oil an 11 x 7 casserole dish.
Puree the roasted poblano in a food processor until smooth.
Bring a large pot of heavily salted water to a boil. Scoop in the cauliflower florets and blanch for 4 to 5 minutes until just tender. Drain and rinse under cold water to stop the cooking. Spread onto towels and let the florets dry completely. Once dry, transfer them to a large bowl.
In a 4 quart saucepan, melt the butter over medium heat. Once the butter had melted, add the shallots and cook for several minutes or until the shallots have softened. Stir in the flour and continue stirring for 2 minutes to make sure that the flour has cooked. Whisk in the heavy cream slowly so you don’t get lumps in your sauce. Then stir in the queso anejo and the poblano puree. Bring the mixture back to a boil and continue stirring until the sauce has thickened. Remove it from the heat, season with 1 teaspoon salt and pour over the cooked cauliflower. Using a rubber spatula, gently toss the cauliflower to coat. Scrape the mixture into the prepared casserole dish.
In a separate bowl, mix together the panko crumbs, almonds and 1 tablespoon olive oil. Sprinkle the crumb topping over the top of the cauliflower and place into the preheated oven on the center rack. Bake for 15 to 20 minutes or until the top has browned. Remove the casserole from the oven and sprinkle the remaining 3 tablespoons queso anejo over the top.
*From Rick Bayless