To roast the red pepper, char on all sides directly on the burner of a gas stove, or roast at 200°C/400°F until blistered all over. Transfer to a bowl until cool enough to handle, then peel off the skin and remove seeds and stem. Roughly chop the pepper before using.
In a food processor, blend the roasted red pepper, spring onions, lemon juice, cumin, salt, 2 teaspoons of pomegranate molasses, ½ teaspoon red pepper flakes and 4 tablespoons olive oil. Add most of the toasted walnuts, reserving a few for garnish. Process until the mixture is mostly smooth.
Add the torn white bread to the processor and pulse until integrated and the spread has a good consistency. If it is too loose, add a bit more bread. Adjust the seasoning with additional salt and red pepper flakes if needed.
Transfer the spread to a serving bowl. Create a small well in the centre using a spoon.
Drizzle 1 tablespoon olive oil and 1 teaspoon pomegranate molasses into the well. Sprinkle the remaining ½ teaspoon red pepper flakes over.
Crush the remaining walnuts by hand and scatter them on top, along with fresh pomegranate seeds if using.