Preheat the oven to 425 degrees.
Bring at least 4 quarts of water to a boil and add 1 tablespoon of kosher salt. Add your macaroni to the water and make sure to agitate the pasta until the water comes back to a boil to prevent the macaroni from sticking to itself. Cook until the macaroni is not quite al dente. It will continue to cook in the oven. Strain from water and set aside.
Heat 1 tablespoon of olive oil in a sauté pan over medium heat. Add your onions and sauté until translucent. Then add your hatch chilies and garlic and cook for about a minute, making sure to scrape the pan to keep the garlic from burning. Remove from heat and set aside.
In a heavy bottomed pot that will fit your macaroni, heat your butter over medium heat until melted and add the flour whisking constantly, making sure no clumps of flour form in your roux. Keep whisking until the mixture starts to turn blond and takes on a light nutty smell. Keep whisking and slowly add your warmed milk. Let cook, stirring for another minute. Then add your cheese and let cook another minute. Remove from heat. Then add the cooked pasta, hatch chili mixture, paprika, orange zest, and salt and pepper to taste. Stir to coat the pasta and distribute the ingredients evenly.
Pour the mixture into a shallow baking dish or distribute between several oven-proof ramekins.
Mix the melted butter with the panko and then lightly distribute the panko mixture over the macaroni and cheese.
Put in the oven and cook until the topping is golden brown and the sauce has thickened.