Separate the outermost leaves of the cabbage. Try not to break them. Soak in boiling-hot water cooking over low heat until they are tender but firm. Soak in ice cold water until it cools to room temperature.
Remove from the water, discard water and set aside the leaves.
For the filling.
Pulse garlic, basil, bell pepper, onion, 1 teaspoon of salt, and pepper in the food processor until you obtain a coarse paste.
Scoop this paste onto the ground beef and mix well.
Heat 2 tablespoons of oil over medium heat. Add the ground beef and brown. Add water and the tomato sauce. Simmer covered until the meat is cooked through and the juices have evaporated (about 15 mins.).
Mix the rice with the meat and remove from the heat. Cool to room temperature and set aside.
Prepare the sauce for serving
Heat a tablespoon of olive oil in a skillet over low heat.
Add the tomatoes and garlic.
Cover and simmer until the tomatoes are cooked through, mash them with a potato masher. Add a teaspoon of oregano, sugar and salt and pepper to taste. Set aside.
How to make the cabbage rolls
Preheat oven to 400 ºF [200 ºC]
Put 2 tablespoons of the rice and beef mixture in the center of one of the leaves. Wrap tightly (using more leaves if necessary) securing the bundle with a toothpick if necessary.
Place the pockets in a baking pan and cover with the sauce. Bake for 15 minutes.
Remove the toothpicks, if you used any, and serve immediately.
I have to say that I'm not very fond of making any dish that requires wrapping (looking at you, pasteles en hoja!). Working with the cabbage leaves is kind of messy, so I don't have any advice on how to do it, so just wing it.