In a bowl, stir to combine eggs and melted (but cold) butter. Add semolina and stir to combine to get a thick mixture. Place in the fridge for 10 minutes. Using two teaspoons, shape the batter into a dumpling and drop it into the pot filled with boiling salted water. Repeat the process until you use all the mixture. Cook for 30 minutes (low simmer). Remove from the heat, cover with a lid, and leave the dumplings to sit in the water for about 20 - 30 minutes. Meanwhile, make the chicken stew.
Place a large pot with olive oil and butter over medium heat. Add chopped onion, sliced carrots, and sliced celery. Cook for 5 minutes, stirring occasionally. Add diced garlic, grated ginger, diced lemongrass (optional), tomato paste and herbs (bay leaf, lemon peel, and thyme). Cook for a minute, then add the chicken breasts cut in cubes, stir and cook for 5 minutes, stirring occasionally. Add the flour, stir and cook for another 5 minutes.
Pour the chicken stock or water into the chicken stew. Bring to a boil, then cover with a lid and cook for 35 - 40 minutes on low heat (simmering). Add the peas, cauliflower and chopped spring onion. Cook for 10 minutes, then season to taste with salt and pepper and drizzle with lemon juice.
Drain the dumplings and divide them between four plates. Add the chicken stew and serve with chopped parsley.