I wish I had written down exact measurements, but I didn't and I'm quite certain this is one of those recipes that you could just kind of throw whatever in. Here is what I remember.
1 large zucchini,
1 1/2 cups fresh tomatoes, diced and drained or 1 can diced tomatoes drained
1/2-1 cup cooked rice
1/2 cup shredded cheese, I used Monterrey jack
1/2 cup diced zucchini (use the stuff you hollow out)
Garlic Salt to taste ( I actually used Johnny's garlic spread & seasoning which I bought at Costco)
1. Cut the zucchini into 2-3 inch sections. Making sure it is a flat cut so they will sit on a cookie sheet nicely. So it is like a cup
2. Scoop out the inside of each "cup" leaving at least 1/4 inch of flesh on the bottom and around the sides, so things don't leak out. The sides you can get a little closer but not too much or it will cave in.
3. Dice the scooped zucchini up to add to the rest of the ingredients. Mix remaining ingredients in a bowl until well blended.
4. Put the mixture into each cup.
5. Spray a cookie Sheet with cooking spray
6. Put stuffed zucchini cups on tray
7. Bake for 20-30 minutes @350°
I checked mine at 20 minutes and they needed just a bit longer. You could also add more cheese to the top at this point and then cook a few minutes longer if you like a lot of cheese. Something I hope to try in the future would be to add sauteed onions and garlic to the mixture.