Preheat the oven to 220°C fan. Add the capsicum, onion, garlic and eggplant to one or two large roasting trays, keeping everything in a single layer.
Drizzle the vegetables with 1 tablespoon olive oil and season generously with salt and pepper. Toss well, then roast for 25 - 35 minutes, until soft and caramelised around the edges. Remove the garlic earlier if it begins to darken too much.
Meanwhile, cook the orzo in a large saucepan of generously salted boiling water according to the packet instructions. Drain when just tender, reserving a little pasta water.
Keep the roasted eggplant separate. Transfer the roasted capsicum, onion and garlic to a blender. Add the smoked paprika, chilli flakes and approximately 200ml stock, then blend until completely smooth.
Toss the prawns with the remaining ½ tablespoon olive oil, grated garlic, lemon zest, chilli flakes, salt and pepper.
Heat a large frying pan over high heat. Cook the prawns for approximately 60 - 90 seconds per side, until golden and only just cooked through. Cook them in batches if necessary to avoid overcrowding the pan.
Add the cooked orzo, roasted eggplant, baby spinach and capsicum sauce to a large pan. Stir over low heat until everything is coated and the spinach has wilted. Add a splash of stock or reserved pasta water if the sauce needs loosening.
Stir through the lemon juice and fresh herbs, then taste and adjust the seasoning.
Divide the orzo among four bowls or meal-prep containers and top with the prawns and extra herbs.