### Slow Cooker Cabbage Roll Casserole

#### Ingredients:
- 1 head of cabbage, chopped
- 1 ½ lb ground beef
- 1 TB tomato paste
- 14 oz tomato sauce
- 1 red pepper, chopped
- 1 green pepper, chopped
- 1 white onion, chopped
- Salt and pepper to taste
- 2 TB garlic powder
- 1 cup uncooked rice (preferably parboiled or converted rice)
- 2 cups beef broth
- 1 cup shredded mozzarella cheese (optional, for topping)

#### Instructions:

1. **Prepare the Vegetables:**
   - Chop the cabbage, red pepper, green pepper, and white onion.

2. **Brown the Ground Beef:**
   - In a large skillet, brown the ground beef over medium heat until fully cooked. Drain any excess fat.

3. **Cook the Vegetables:**
   - Add the chopped onion, red pepper, and green pepper to the skillet with the ground beef. Cook until the vegetables are tender.

4. **Add Tomato Paste and Sauce:**
   - Stir in the tomato paste and tomato sauce. Mix well to combine.

5. **Season:**
   - Add the garlic powder, salt, and pepper to taste. Stir to combine.

6. **Prepare the Slow Cooker:**
   - In the slow cooker, spread half of the chopped cabbage evenly on the bottom.

7. **Layer the Ingredients:**
   - Pour half of the beef and vegetable mixture over the cabbage layer, spreading it out evenly.
   - Sprinkle the uncooked rice evenly over the beef and vegetable mixture.
   - Add the remaining chopped cabbage on top of the rice layer.
   - Pour the remaining beef and vegetable mixture on top of the cabbage layer.
   - Pour the beef broth over the entire mixture.

8. **Cook:**
   - Cover the slow cooker and cook on low for 6-7 hours or on high for 3-4 hours, until the cabbage and rice are tender.

9. **Add Cheese (Optional):**
   - If using cheese, sprinkle the shredded mozzarella on top during the last 15-30 minutes of cooking. Cover and cook until the cheese is melted.

10. **Serve:**
    - Let the casserole rest for a few minutes before serving. Serve hot and enjoy!

#### Food Science Principles to Consider:
1. **Browning the Meat:**
   - Browning the ground beef before adding it to the slow cooker enhances the flavor through the Maillard reaction, which creates complex flavor compounds.

2. **Layering:**
   - Layering the ingredients ensures even cooking and helps the flavors meld together. Placing the cabbage on the bottom and top helps protect the rice from direct heat, ensuring it cooks evenly.

3. **Rice Selection:**
   - Using parboiled or converted rice is recommended for slow cooker recipes because it holds up better during long cooking times without becoming mushy.

4. **Liquid Balance:**
   - Adding the right amount of beef broth ensures the rice cooks properly and the casserole remains moist. Too little liquid can result in undercooked rice, while too much can make the dish soupy.

5. **Cooking Time and Temperature:**
   - Cooking on low heat for a longer period allows the flavors to develop fully and the ingredients to cook evenly. However, cooking on high for a shorter time can be used if you're in a hurry.