Place the minced meat into a bowl and add the egg. Season with salt and pepper.
Grate the stale bread into the mixture using a fine grater. Grate in the garlic as well.
Wash the oregano, strip off the leaves, chop finely, and add to the meat mixture.
Mix everything thoroughly. With wet hands, shape the mixture into walnut-sized meatballs and place them on a plate.
Finely chop the onion and sauté it in olive oil in a medium-sized pot until golden brown.
Remove the pot from the heat and add the green beans, peas, and corn. (If using frozen vegetables, they may sizzle a little.) Quickly pour in enough water to cover them. Season with salt and pepper, add the oregano sprigs, and bring to a boil.
Once boiling, add the meatballs and cook until they are tender.
Stir in the cooking cream and simmer for about 5 more minutes.