Wash the courgette, cut into 4 pieces and hollow out most of the flesh with a spoon.
Blanch in boiling salted water for 2 minutes, drain, plunge into cold water and pat dry.
Clean the mushrooms and remove the stalks. Dice the stalks finely. Wash the tomatoes, cut a lid off each one and hollow out the centre. Dice the lids of the tomatoes. Also dice the courgette flesh.
Bring the stock to the boil in a pan and sprinkle in the couscous. Remove from the heat and stand for 5 minutes.
Heat the oil in a pan.
Saute the diced mushrooms and courgettes for 2-3 minutes. Add the tomatoes, season with salt and pepper and remove from the heat.
Mix the crème fraîche with the parsley and the pan-fried vegetables.
Finely dice the feta and add half to the vegetables with the paprika. Mix well. Preheat the oven to 180°C (160°C fan, gas 4).
Spoon into the tomatoes, mushroom caps and courgettes.
Place in an oiled baking tray.
Scatter the remaining feta on top and bake in the oven for 25 minutes.