For about $20-25 US (not sure where you are) you can get a digital meat thermometer with a cord that trails out the oven/BBQ door and beeps when the meat is perfectly cooked. Something like [URL="http://www.amazon.com/Polder-Digital-In-Oven-Thermometer-Graphite/dp/B000P6FLOY/ref=sr_1_2?s=home-garden&ie=UTF8&qid=1347144908&sr=1-2&keywords=meat+thermometer+digital"]this from Amazon[/URL] if you don't have a Target or something similar.
I'm notorious for overcooking meat and make it totally dry, but this makes it come out perfect every time.
Saute up some fatty ground beef, breaking up in the pan as you cook. When the the chunks are all some degree of brown, throw in any chopped veggies. Stir fry for several minutes until the veggies are cooked to your liking. Salt and pepper at the end.
When I'm really rushed to get home from work and dinner on the table, I throw together a homemade version of a Chipotle bowl.
Take the meat off a rotisserie chick. (take it all off, save the bones for broth, save the rest of the meat for another meal)
Dump handful in a bowl.
Brown some onions and peppers with some spices (salt, pepper, red pepper flakes), throw on top.
Cut up an avocado or mash into quac, put on top
Top with cheese and/or sour cream if you do dairy
Add chopped lettuce