Preheat your oven to 180°C (350°F).

Prepare the vegetables by trimming the fennel and cutting it into wedges, and slicing the onion into rings. Combine them with unpeeled garlic cloves in a large roasting dish. Drizzle with oil, season with salt and pepper, and toss to coat.

Roast the mixture in the preheated oven for 25-30 minutes until the fennel is soft and browned.

Squeeze the roasted garlic out of its skins and add it back to the roasting dish. Stir to incorporate.

In a large saucepan, bring the vegetable stock to a gentle boil, then add the roasted ingredients and frozen peas. Simmer for 5 minutes.

Blend the soup until smooth using a hand blender or food processor.

Stir in coconut milk, lemon juice, baby spinach, and parsley. Blend briefly to combine and adjust seasoning with salt and pepper.