Pre-heat oven to 400 degrees Fahrenheit.
On a pan, heat 1 tablespoon of butter and add the Panko breadcrumbs. Stir-fry until they are slightly golden and set aside for baking.
Cook pasta according to packaging’s instructions. Drain off excess water and set aside.
To make the beef, heat 1 1/2 tablespoon of oil on a pan. Cook garlic, red onions, and jalapeño pepper over medium high heat until they are fragrant and tender, about 1 minute. Add in the ground beef and cook while also separating them into smaller pieces. When the beef are browned and cooked, about 3-5 minutes, add the Taco seasoning, salt, and pepper and stir well. Remove from heat and set aside.
To make roux for the mac and cheese sauce, melt 2 tablespoons of unsalted butter on a pan over medium high heat. Add 2 tablespoons of flour and mix using a whisk until there are no more visible raw flour, about 30 seconds. Pour in 1 cup of milk and stir well using a whisk, breaking off the bigger pieces of the roux. Once the sauce thickens, add another 1 cup of milk. Stir until the sauce thickens again (you can make a path along the bottom of your pan using your spatula, but the sauce is still runny). Add in the cheese, Taco seasoning, salt, and pepper to taste. Mix in the cooked macaronis, cooked beef, tomatoes, olives, and fresh jalapeño into the sauce and combine well.
To bake, transfer the mac and cheese into a baking dish and top with cheese and the buttered Panko breadcrumbs. Bake for 7-10 minutes or until the cheese is fully melted and the Panko breadcrumbs are golden brown. Serve with cilantro.