My favorite quick low-carb meal is taco salad ... If I'm in a hurry, I brown low-fat ground beef or ground turkey, season and simmer. While the meat is simmering, I tear up some butter crunch lettuce, chop a tomato, maybe an avocado, or sweet red onion, and shred some sharp cheddar cheese. I generally use ranch dressing over the salad, which has just a little bit of carb in it, but if you're content with salsa for dressing, this is an almost NO CARB meal.
If you need something just a little more "stick-to-your-ribs" than just salad, warm up a can of refried beans, and add a little cheese. Serve on side or over salad.
In 20 minutes, I have a full meal ... This works well for my (non-diabetic) husband, too, since he can use all these ingredients to make his own burritos or tacos. I skip the tortillas, myself.
When there's time to plan ahead, I put a pork or beef roast in the oven, smother with salsa, cover, and roast at 325 (F) for about 3 hours. When you take the meat out it shreds quickly and easily. Take a fork in each hand, stick both in the roast, and pull in opposite directions. Use pulled pork or beef instead of ground beef over taco salad. Makes great sandwiches for husband, too.
If you'll be out of the house all day, the roast could be adapted for crockpot cooking.