Zucchini casserole in the oven

Ingredients:

• 1 tablespoon canola oil, plus more for greasing the pan
• 3 yellow zucchini, cut into 0.6 cm thick slices (about 450 g)
• 1/2 head sweet onion, chopped
• 4 zucchinis, cut into 0.6cm thick slices (about 450g)
• 1 tbsp flour
• 1 cup low-fat milk
• 1.25 tbsp. grated cheddar
• 2 large eggs, lightly beaten
• 1 tbsp. panko breadcrumbs
• 1/4 cup chopped mixed fresh herbs such as parsley, chives

Preparation:

1. Preheat oven to 180°C. Grease an ovenproof baking dish with oil.
2. Bring a saucepan of water to a rolling boil over high heat. Place the yellow squash and onion in a steamer basket and set it over the simmering water; steam until the squash is tender. Repeat with the zucchini and steam until soft. (You can also place all the vegetables in a microwave-safe bowl and steam them until tender, about 4 minutes, depending on the power of your microwave.) Transfer the vegetables to a large bowl.
3. Heat canola oil in a saucepan over medium heat. Add flour and stir until very light brown. Add milk and stir until smooth. Bring to a boil over high heat, then remove from heat. Add 1 cup of cheese and stir it into the sauce. Taste and season with salt and pepper.
4. Pour the sauce over the zucchini and onion; mix well. Add the eggs, half the breadcrumbs, and herbs, and mix well. Transfer the mixture to a prepared ceramic or ovenproof glass dish. Mix the remaining half of the breadcrumbs and 1/4 cup of cheese and sprinkle them over the zucchini mixture.
5. Bake until set and golden brown on top, 30 minutes. Transfer to a wire rack and cool slightly before serving.