Peel and chop the onion. Heat the oil and fry the onion until transparent. Add lentils and steam briefly. Add stock and cook for about 1 1/2 hours. Peel and wash the potatoes.
Add them to the lentils about 30 minutes before the end of the cooking time and cook them. Melt the fat in a saucepan. Add flour and sauté while stirring. Gradually stir in milk. Season the sauce with lemon juice, curry, salt and pepper, simmer for about 10 minutes at low heat. Cook eggs in boiling water for about 6 minutes. Clean, wash and cut spring onions into rings. Add spring onions and lentil-potato vegetables to the sauce with the broth and mix. Season to taste again. Quench eggs cold, peel and halve.
Cook eggs in boiling water for about 6 minutes. Clean, wash and cut spring onions into rings. Add spring onions and lentil-potato vegetables to the sauce with the broth and mix. Season to taste again. Quench eggs cold, peel and halve. Fill vegetables into a terrine, arrange egg halves on top. Dust with curry if necessary.