This was something my mother came up with recently, and it's simple enough for me to not only make from her notes, but to make with tofu substituted for the ground beef for a vegetarian variant. There's a lot of balls to keep in the air at once, but it can also be prepared in stages. It's also very forgiving of emergency substitutions, so I'd love to hear of any variations on this y'all try.

Ingredients
1 pound ground beef or turkey or tofu
1 package taco seasoning or whatever you do to make taco meat
1 1/2" Velveeta cheese
1/2 cup milk
2 cups pasta - I like spirals but whatever
1/2-1 cup frozen peas/corn/whatever vegetable medley keeps you from dying
Equipment
large skillet
pasta pot
microwave-safe measuring cup or bowl, 2 cups or bigger
If you don't want to juggle too many things at once, make the macaroni right off before anything else, because that's the least time-sensitive of the three components.
1. Prepare The Pasta
Fill up a big pot, throw it on the stove, throw noodles at it when it's boiling. Let noodles boil for 8 minutes, then drain.
If you don't want to juggle multiple tasks at once, you can make the pasta early and set it aside before you do anything else.
2. Prepare The Meat
If you make taco meat on a regular basis, do that.
If you're a benighted soul who doesn't do tacos regularly, throw the ground beef/turkey/tofu(after suitable draining/pressing/baking) into the skillet on the stove. Break it up and brown it. Then add water and taco seasonings as directed on the packet.
3. Add vegetables and noodles to the meat. Cook for 5 minutes, while you do the next step.
4. Cut Velveeta into cubes about the size of the fingertip and throw into the measuring cup or bowl. Microwave on high for 2-3 minutes, then stir until smooth.
5. Add cheese sauce to your pan. Stir until everything's all blended together in sticky cheesy glory.
Eat. It will kill you, but you won't regret it.