Soak the buns. Clean and wash the vegetables. Leave cauliflower and carrots whole, cut broccoli into florets. Cook cauliflower in boiling salted water for 20-25 minutes, carrots for 15 minutes and broccoli for the last 8 minutes
Peel and chop the onion. Knead with pressed bread roll, mince, mustard, salt and pepper. Form 8 meatballs from it. Wrap 1 bacon slice around each. Fry the minced steaks in hot oil all around for 12-15 minutes
Drain the carrots and broccoli. Lift out the cauliflower. Measure out 300 ml vegetable water. Heat butter in a pot. Sauté flour in it. Deglaze with vegetable water and milk while stirring. Bring to the boil and simmer for about 5 minutes
Mix the egg yolks and 3-4 tablespoons of sauce. Stir into the hot sauce (do not boil any more!). Season to taste with salt, sugar, nutmeg and lemon juice. Arrange minced steaks and vegetables. Spread the sauce over the vegetables. Sprinkle with chervil