Soak morels in hot water for about 20 minutes. Rinse chicken breast, pat dry and cut into about 5 cm (approximately 2-inch) cubes. Season with salt and pepper.
Peel garlic and chop finely. Heat 50 grams (approximately 3 1/2 tablespoons) of butter in a pan and sauté carrots, celery, leeks, onion and garlic while stirring. Add chicken breast fillets and sprinkle with flour. Add rest of butter in chunks and sauté everything, stirring.
Preheat oven to 50°C (approximately 125°F) degrees. Add bay leaves, parsley and thyme to vegetables and meat. Deglaze with white wine and simmer for about 6 minutes. Pour in chicken stock and simmer covered for about 12 minutes.
Remove meat and keep warm in oven. Remove bay leaves, parsley and thyme. Pour sauce through a sieve into a saucepan, add the cream and let boil for about 5 minutes.
Stir yolks into sauce. Remove morels from water and squeeze. Add with meat and diced vegetables into sauce and heat but do not boil. Season with salt, pepper and lemon juice. Serve with rice.