Heat your pot over medium heat. While waiting, prepare and organize all your ingredients.
Put butter in the pot and let it melt. Add the chopped onions and cook until they look clear and soft, around 3-4 minutes. Add the minced garlic and cook until you can smell its aroma, about 1 minute.
Add the diced beef cheeks and cook until they turn brown on all sides, about 5-7 minutes. Pour in the beef stock and wait for it to boil.
Once boiling, add your diced carrots and corned beef. Lower the heat and let it cook slowly for 40 minutes, or until you can easily cut through the beef with a spoon. Stir every now and then, and add hot water if the liquid gets too low.
When the beef is tender, add your macaroni, thyme, and basil. Cook for another 15 minutes, stirring gently until the macaroni is cooked but still a bit firm when you bite it.
Pour in the evaporated milk and stir carefully. Let it heat just until you see tiny bubbles, then turn off the heat right away. You don't want the milk to form lumps.
Add salt and black pepper to taste. Let it sit for 5 minutes - this makes it taste even better.
Serve hot in bowls. If you like, you can add chopped green onions on top. Enjoy with toasted pandesal on the side.
For leftovers, let it cool completely before storing in the refrigerator. When reheating, do it slowly over low heat, stirring gently. Add a splash of hot water or stock if it's too thick.