1. Preheat your oven to 180°C (350°F).
2. Bring a large pot of salted water to a boil. Add the whole grain pasta and cook according to package instructions until al dente. Drain and set aside.
3. While the pasta is cooking, wash the eggplant, remove the ends, and cut it into small cubes.
4. In a large pan, heat the olive oil over medium heat. Add the chopped onion and sauté for 3-4 minutes until translucent.
5. If using garlic, add it to the pan and cook for an additional minute.
6. Add the minced beef to the pan and cook until browned, breaking it apart with a wooden spoon (about 5-7 minutes).
7. Stir in the eggplant cubes and cook for another 5 minutes, until they have softened.
8. Add the diced tomatoes and a pinch of oregano or basil. Mix well and let it simmer for 5-10 minutes. If the mixture gets too dry, add a small amount of water.
9. In a baking dish, combine the cooked pasta with the beef and eggplant mixture. Stir until well combined.
10. Bake in the preheated oven for about 20 minutes until heated through and slightly golden on top.
11. Allow to cool slightly before serving to your toddler.

Summary:
This Beef and Eggplant Pasta Bake is a delicious, nutritious lunch option for toddlers over 10 months old. It combines wholesome ingredients that are full of flavor while being easy for little hands to grasp and eat. The dish is rich in protein from the beef and provides fiber from the whole grain pasta and eggplant.

Storing Options:
Keeping leftovers in an airtight container in the refrigerator for up to 3 days. You can also freeze portions for up to a month.

Possible Side Effects/Allergies:
Awareness of possible allergies to be aware of include eggplant (nightshade family), wheat in the pasta, and any reactions to beef. Always consult your pediatrician if you are introducing new foods to your child's diet.