1. Cook the Bulgur:
   - Rinse 50 grams of bulgur under cold water.
   - In a small pot, bring 500 ml of water to boil.
   - Add the rinsed bulgur to the boiling water.
   - Reduce the heat and let it simmer for about 10-15 minutes or until tender.
   - Drain any excess water and allow the bulgur to cool completely.
2. Prepare the Fruits:
   - While the bulgur is cooling, remove the seeds from the 150 grams of watermelon if needed, and cut it into smaller chunks.
   - Rinse 100 grams of blueberries thoroughly under running water.
3. Blend the Ingredients:
   - In a blender, combine the cooled bulgur, watermelon chunks, and blueberries.
   - Blend the mixture until you achieve a smooth puree consistency.
4. Serve:
   - Test the puree's temperature to ensure it's not too hot or too cold.
   - Serve the puree to your baby in a small bowl or directly from the blender jar, depending on your baby's eating preferences.

Summary:
This recipe combines the nutritious benefits of bulgur, watermelon, and blueberries, providing essential vitamins and minerals for your baby's growth and development. The natural sweetness from the fruits makes it a delicious and appealing snack.

Storing Options:
You can store any leftover puree in an airtight container in the refrigerator for up to 2 days. Always check the puree for freshness before serving it again.

Possible Side Effects/Allergies:
Always introduce new ingredients to your baby's diet gradually to monitor for any potential allergies. Although it's rare, some babies may develop allergic reactions to blueberries and less commonly to watermelon. Signs of allergies can include rashes, swelling, or digestive discomfort.