It's pretty simple.
Over medium/low heat you heat up the tomato juice, with most of the chili powder, (some goes into the meat), slowly (you really don't want it to boil), as you heat up the water you cook the pasta. You just want the pasta cooked but still firm.
As the liquids heat up you will want to cut the cheese up. As long as the chunk isn't thicker than 3/4 inch, you're okay. Store in a cool place, covered, until later. Fridge is best.
Start to brown the meat up, you might want to add the chili powder half way through the cooking.
Drain pasta and add straight to the Tomato juice. Take off heat completely. Add thoroughly cooked meat and cheese. Stir it once, if you stir more than that it will come out VERY grainy.
Let it sit for 5 - 10 for cheese to melt. Will be very soupy. If you want it thicker you just add more pasta.