I cook up big batches of sweet onions until translucent, let them cool and portion into ice cube trays. When hardened, I pop them out into a zip top bag and store in the freezer. When a recipe calls for cooking onions, I zap a cube or two on high in the microwave for a minute. I save myself LOTS of time every week chopping and sweating onions! (I also freeze chopped red or green peppers the same way for the same reason.)
HAMBURGER MEAT in an INSTANT
When ground beef is on sale, I buy several pounds of it (3-6) and brown ALL of it in a huge pot. I skim out the fat with a turkey baster as it cooks,then I let it cool and package it in one pound increments in individual zip top bags. Then, I lay them FLAT in the freezer to harden. Laying them flat allows for efficient space utilization in the freezer and SPEEDY thawing! They thaw in no time (in warm water or in the microwave). I then have quick access to cooked hamburger for: tacos, chili, Tamale pie, stuffed peppers, spaghetti sauce, etc. MAJOR time saver!