Preheat the oven to 180 °C.
Halve the pumpkin and remove the seeds with a spoon. Place the pumpkin halves in an ovenproof dish. Place the whole garlic cloves in the pumpkin, along with the sprigs of thyme. Season with salt and pepper and pour some olive oil over the top. Place in the oven for 1 hour or until the squash is completely soft. Quarter the onions and place them in the oven with the squash for the last 20 minutes.
Remove the baking dish from the oven when everything is cooked. Spoon the flesh out of the pumpkin and put it in a deep pan. Add the onions, garlic and thyme leaves (not the sprigs). Pour in 0.75 liters of water and blend with a hand blender. Taste and season if necessary. Put the soup on the stove, but do not let it boil. Dissolve the miso in a glass with a few tablespoons of the soup and add it to the rest of the soup (see tip).
Slice the mushrooms and sauté until tender in olive oil. Season with salt and pepper. During the last 3 minutes, add the pumpkin seeds.
Divide the soup among plates, arrange the mushrooms and pumpkin seeds in the center and crumble the feta over it.

Tip: miso
Miso adds an extra dimension to your pumpkin soup, but it is not essential. Miso is described as the fifth flavor, umami, a typical taste found in fermented products such as cheese. If you want to fully enjoy the benefits of fermentation, don't let miso cook with it, as the live bacteria will die. Let the soup cool first and only then add the miso.

Tip: winter version
The Real Food book is not a seasonal book; be guided by the seasons. In winter, choose winter squash with delicious wild mushrooms such as chanterelles and trompettes de la mort. In summer, we often eat this soup cold, as a kind of gazpacho.