Buy a box of tomatoes for $6. (When in season...) Take the skins off so that you can turn the tomatoes into passata. Bake skins in oven at 70=80C for 2-4 hours. Put them in food processor and then mortar and pestle. Result = tomato powder or tomato dust. Tastes fantastic and will be used in/on meals.
Stay tuned. I have another load of skins to do tomorrow. But clearly, oven drying is an energy-intensive exercise. This sounds a bit dumb, but how to sun-dry them? Easy to put them outside on a tray. I just need to keep the bugs and dust off them.... How do you do that?