Here is a recipe I adapted from a co-worker. They are really good...and simple to make.
Just a note: my peppers were so large I had to use two large crock pots at the same time, 4 in one and 3 in the other. If you have an oval crock pot, you can fit more inside. Look for peppers with good flat bottoms that don't have the bottom end curling back up inside.
2 lbs ground beef
4-8 large clean green peppers depending on your crockpot
1 box Spanish rice mix
14 oz can tomato sauce (I used 28 oz since I had 7 peppers.)
14 oz can diced tomatoes for rice.
1 small onion, diced
2 cloves garlic, minced (I'm lazy so I use the stuff in a jar.)
Saute the minced garlic and onion til soft but not browned. Add the ground beef and brown.
Pour off any grease.
Add 1-2 teaspoons salt, 1/2 teaspoon pepper and 2 tablespoons Worcestershire sauce.
Mix well and set aside to cool a bit.
While the rice is cooking, clean your peppers, then cut the tops off and hull out them out of seeds and ribs.
Check for brown spots on the inside of your peppers and scrape them off if you find any.
Mix your rice and beef mixture, taste and adjust seasonings if needed.
If you like cheese, do this part, if not, skip it.
Here, I added a couple of large handfuls of shredded cheese to the mix. (f you do this while the mixture is warm, work FAST...)
Spoon the mixture into the shells, packing it in up to the top, then carefully set them aside. You want them all packed evenly.
Spray your crock with Pam up the sides for easy cleanup.
Pour a little tomato sauce in the bottom of the crock.
Stand your peppers up and tightly squeeze them into the crock. You don't want them slumping over once they start softening from being cooked.
Pour the rest of the tomato sauce over the peppers, sprinkle with salt and pepper and top with cheese. I prefer them with cheese, it also helps keep everything together once the pepper softens.
Cook on low about 8 hours or 6 hours on high. Peppers can be tricky, if they are thin skinned, they may cook faster and get mushy so keep that in mind when setting your temp.
Spoon a little of the sauce that collects in the bottom of the crock........and enjoy!