In a large skillet (mine is 13") cook the ground beef over medium-high heat for about 5 minutes. Add the diced onion and cook for an additional 2 minutes. Drain any excess fat or grease.: The first aromas you will notice are deep, toasty meat notes and a light sizzle as the ground beef hits the pan, indicating the Maillard reaction that builds savory flavor. Use a sturdy Cast Iron Skillet if you have one, because it maintains even heat. As the meat browns break it up with a spoon so pieces are small and uniform, that helps even seasoning distribution. A common mistake is crowding the pan which causes steaming instead of browning, so give the skillet room and brown in batches if needed. When the meat is richly colored with little browned bits, you are ready for the next step.
Stir in the corn, black beans, tomatoes and chilis, taco seasoning, black pepper, chili powder, water, and bring to a boil.: You will hear a softened sizzle and smell a sweet, savory lift as the onion turns translucent, which mellows its sharpness. Stir frequently so edges do not char, and lower the heat if they start to brown too fast because burnt onion will impart bitterness. The softened onion blends into the meat, creating a base that carries the taco spices. A common misstep is undercooking the onion, leaving a raw bite that competes with the sauce rather than harmonizing.
Add the elbow macaroni to the skillet and mix well until fully combined.: Pockets of hot fat can make the final dish greasy and heavy, so carefully tilt the skillet and spoon out or pour off excess. You should still retain enough rendered fat to coat the pan lightly, which helps bind flavors. Be cautious while removing fat to avoid splatter burns. If you skip draining you may end up with an oily sauce that separates instead of emulsifying, so this small step matters.
Add the cream cheese and stir until mixed well.: A symphony of smells will build as the spices bloom in the hot pan and the tomato juices mingle with the rendered beef juices. Stir so the spices dissolve and distribute evenly, and watch for a rolling boil which is the signal the pasta will cook properly. If the mixture seems too thick before boiling, add a splash more water to ensure the pasta hydrates. A frequent error is not stirring enough, which can cause clumps of seasoning or sticking on the pan bottom.
Reduce the heat to a simmer and cook for 12-15 minutes, or until the pasta is fully cooked and tender.: You will see the elbow macaroni sink and then bob as it hydrates, soaking up the flavorful liquid. Mix to separate any pieces so they cook uniformly, and maintain a gentle boil so water circulates around the pasta. If the pasta layers at the bottom it can clump and cook unevenly; stirring occasionally keeps it free and ensures even texture.
Garnish with cheese and diced green onion (optional) before serving.: The cream cheese will melt into the hot liquid and create a glossy, velvety sauce that coats the pasta and filling. Use a spoon to gently press and swirl the chunks so they dissolve smoothly. If you add cold cream cheese it can form lumps, so soften a bit at room temperature or cube it for faster melting. The goal is a uniform, silky texture; if you see streaks of unmelted cheese, keep stirring over low heat until smooth.
Reduce the heat to a simmer and cook for 12 15 minutes, or until the pasta is fully cooked and tender: During this time the pasta absorbs flavor and the sauce thickens, producing a comforting, cohesive dish. You will hear a softer bubbling and the surface will look creamier as water reduces. Test a piece for doneness; it should be tender with a slight bite and the sauce should cling to it. Overcooking will make the pasta mushy and leach starch that can thicken excessively and turn gummy, so check early and often towards the end.
Garnish with cheese and diced green onion (optional) before serving: As soon as you remove the skillet from heat, sprinkle the shredded Mexican blend cheese so it melts from residual warmth and creates a stretchy, luscious top. The crisp green of the green onions provides freshness both visually and on the palate. A typical mistake is letting the skillet cool too long before serving, which prevents the cheese from melting and the dish from feeling cohesive, so serve promptly for best texture and appeal.