Preheat the oven to 180 degrees Celsius.

Fill a large casserole pan with water 2/3 of the way up. Add a few big pinches of salt and bring to a boil. When the water is boiling add the pasta and stir. Boil the pasta until soft and al dente. Once cooked, carefully strain into a colander and return to the pan.

Meanwhile, place the eggs into a small saucepan and top with water. Bring to a boil and boil for 5 minutes. After 5 minutes, turn off the heat, strain and top with cold water. Peel the eggs and slice into thin slices.

While the pasta and eggs are cooking, add the butter to a large, shallow casserole pan on a medium heat. Once melted, add the onions and sauté until translucent. Add the minced garlic and sauté until fragrant.

Add the rice flour and corn starch to the pan and stir to combine with the melted butter, onions and garlic. Pour in a third of the milk and whisk straight away. Add another third and whisk and then the final third and whisk until there are no lumps. Add the brine from the tuna and whisk to combine. As the sauce starts to thicken, add the chicken stock and continue stirring until smooth and creamy with no lumps. The mixture should be thick enough to coat the back of a wooden spoon.

Add the dried thyme, salt and pepper to the sauce and stir to combine. Add the baby spinach and stir through to wilt the spinach. Once the spinach is wilted, turn off the heat.

Add the tuna to the sauce and use the spatula to break up any lumps. Add the peas, broccoli, corn kernels, sliced eggs and strained pasta and toss through the sauce so that all of the components are coated in sauce and evenly distributed.

Add grated mozzarella and cheddar to the top of the tuna casserole. Place the pan into the oven and bake for 35 minutes or until the top is turning golden.