Preheat the oven to 220C/200C Fan/Gas 7.
Place the fennel wedges in a large 28cm/11in round flameproof baking or cast-iron dish over a high heat. Drizzle over the oil and 1 teaspoon salt. Char the fennel for about 5 minutes on each side until caramelised.
Pour 750ml/1¼ pint boiling water into a large jug and whisk in the miso, mustard, bouillon powder and 1½ teaspoon salt to make a broth.
Add the broth, orzo, chickpeas, spinach and artichokes to the dish and stir. Place the lemon slices over the orzo. Cover tightly with a lid or silver foil and bake for 25 mins, then remove the lid and bake for another 5 mins, until the liquid has been mostly absorbed.
Meanwhile, to make the pesto, toast the pine nuts on a baking sheet on the lower shelf of the oven for about 5 minutes, or until golden.
Mix the rocket, reserved fennel fronds, toasted pine nuts, lemon juice, oil and Aleppo pepper (if using) in a bowl.
Drizzle the pesto over the orzo and serve.
