1. Preheat your oven to 180°C (350°F).
2. In a medium pot, bring water to a boil and cook the quinoa pasta according to package instructions until al dente. Drain and set aside.
3. In a separate pot, bring 200ml of water to a boil. Add the cauliflower florets and cook for about 5 minutes until tender. Drain and set aside.
4. In a frying pan, heat the olive oil over medium heat. Add the cod fillet and cook for about 4-5 minutes on each side until it's cooked through and flakes easily with a fork. Remove from heat and break the cod into bite-sized pieces.
5. In a large bowl, combine the cooked quinoa pasta, cauliflower florets, and flaked cod. Add the vegetable stock and dried thyme (if using). Mix gently to combine everything without mashing the cauliflower too much. If using salt, add it here as well, ensuring it is minimal.
6. Transfer the mixture to a baking dish and spread it out evenly.
7. Bake in the preheated oven for 20 minutes, or until heated through and slightly golden on top.
8. Remove from the oven and allow it to cool slightly before serving. Garnish with chopped fresh parsley if desired.

Summary:
This Cauliflower, Cod, and Quinoa Pasta Bake is an excellent lunch option for toddlers over 10 months due to its nutritious ingredients and familiar flavors. It provides a balance of protein from the cod, fiber and vitamins from the cauliflower, and carbohydrates from the quinoa pasta. The texture is suitable for baby-led weaning, allowing little ones to pick up pieces and explore their independence while eating.

Storing Options:
Leftovers can be stored in an airtight container in the refrigerator for up to 2 days. This dish can be reheated in the oven or microwave, ensuring it’s warmed through before serving.

Possible Side Effects/Allergies:
Cod is a common allergen, so it’s important to ensure that your child has already been introduced to fish without any adverse reactions. Always check with a healthcare professional if you are unsure about introducing new foods into your toddler's diet.