Preheat the oven to 180°C / 350°F / Gas mark 4.
Line 2 baking trays with greaseproof paper and set aside.
Grease a loaf tin by spraying it with cooking spray and set aside.
Place the peppers skin sides up, on the baking tray.
Cook until blackened.
Put them in a plastic bag or a sealed food storage container.
Let stand for 10 minutes.
Peel the skins off easily and finely chop.
Put the peeled and chopped peppers into a bowl and set aside.
In your food processor, add the mushrooms and pulse until finely chopped.
Transfer the chopped mushrooms to a bowl.
Heat a large non-stick pan over medium heat.
Add the olive oil and swirl to coat.
Add the mushrooms and cook until the liquid evaporates, stirring occasionally.
Add the cooked mushrooms to the peppers and stir to combine.
Wipe the pan with kitchen paper then add the asparagus and onion and cook until just tender, stirring occasionally.
Add the onion and asparagus mixture to the bowl with the other vegetables.
Pulse the bread in the food processor to get a breadcrumb texture.
Arrange the breadcrumbs in an even layer on a baking sheet and bake for 10 minutes or until golden.
Add the breadcrumbs, walnuts, basil, parmesan cheese, eggs, ketchup and Dijon mustard to the mushroom mixture and stir well.
Spoon the mixture into the prepared loaf tin and press gently down with a spatula or the back of a large spoon to pack.
Cook for 45 minutes.
To prepare the topping, combine 2 tablespoons of ketchup and Dijon mustard along with salt and pepper and mix well in a small bowl.
Brush the topping mixture over meat loaf.
Bake for an additional 10 minutes.
Allow the vegetable loaf stand to cool then cut into slices.