Preheat your oven to 200°C (390°F). Line a baking sheet with parchment paper.
Arrange the sliced eggplant, zucchini, and pepper on the baking sheet. Drizzle with olive oil and season with salt and pepper. Roast for about 25-30 minutes until vegetables are golden and slightly caramelized, filling your kitchen with a smoky aroma.
While the veggies roast, heat a tablespoon of olive oil in a saucepan over medium heat. Add the minced garlic and cook until fragrant, about 30 seconds, stirring constantly. Pour in the crushed tomatoes, season with salt, and simmer gently for about 15 minutes to develop a bright, flavorful sauce.
In a separate saucepan, melt the butter over medium heat. Whisk in the flour and cook for about 1 minute until it smells nutty. Gradually pour in warm milk, whisking constantly to create a smooth, thick béchamel sauce. Season with salt, pepper, and a pinch of nutmeg. Cook until thickened, about 5 minutes, then remove from heat.
Once the vegetables are roasted and slightly cooled, layer them in your baking dish. Start with a base of tomato sauce, then add a layer of roasted vegetables, and spoon over some béchamel. Repeat these layers, ending with a generous top layer of béchamel and sprinkle with crumbled feta and grated Parmesan cheese.
Bake the assembled moussaka at 200°C (390°F) for 30-35 minutes until the top is bubbling and golden brown. Loosely tent with foil if the cheese begins to brown too quickly. Let rest for at least 15 minutes before slicing to allow layers to set.
Garnish with chopped parsley or dill, then serve slices warm, enjoying the tender roasted vegetables with their smoky aroma and creamy topping.
