For the rabbit
Season rabbit with salt on both sides. Place a pot over high heat, add half the olive oil and sauté the rabbit until it turns golden brown on both sides. Remove rabbit pieces, add the remaining olive oil and sauté the onion over medium heat. As soon as the onion has softened and turned a light golden colour, add the garlic and, as soon as it has released its aroma, add the tomato. Season lightly with salt, add the stock, bring to the boil and reduce heat. Place the rabbit in the pot, ensuring it is completely covered by the liquid. Cover and cook on a very low heat until the rabbit is soft, approx. 1 ½ to 2 hours. Remove rabbit from the pot and keep warm. Place the pot with the rabbit cooking liquid over high heat and cook until the sauce has reduced to the desired consistency. Add the mushrooms and herbs and season with salt if necessary. Return rabbit to pot and cover with the sauce.
For the mushrooms
Place a frying pan over very high heat. Add the sunflower oil and then the mushrooms in one layer so as not to overfill the pan. (The oil must cover 1/3 of the height of the mushrooms). Cook stirring frequently and season with salt. As soon as the mushrooms have browned, strain, remove onto absorbent paper and season with salt. Repeat process with remaining mushrooms if required.