Soak the pearl barley in cold water overnight, then drain, put into a pan, cover with water and cook for about 1 hour until soft (season well with salt 15 minutes before the end). Strain through a sieve and rinse in cold water.
Peel and very finely chop the shallot.
Wash and sort the spinach and cook in a little boiling, salted water until it collapses. Then drain, refresh in cold water and drain thoroughly. Squeeze out the spinach and chop roughly. Finely dice the pumpkin and cook in boiling, salted water for about 10 minutes. Drain thoroughly.
Heat 1 tbsp oil in a pan and sweat the shallot until translucent. Add the spinach and cook gently for 4 - 5 minutes. Season with 1 tbsp lemon juice, salt and pepper and add the thyme.
Mix the rest of the oil and lemon juice with salt and pepper. Mix the drained barley with the vegetables and salad dressing. Serve the vegetable salad with freshly shaved Parmesan.