Lightly toast the walnut pieces in a heavy-based pan.

Set toasted walnuts aside.

Heat vegetable oil in a pan.

Saute the thinly sliced or chopped onions in the oil until golden brown but not burned.

Add tomato paste to the sauteed onions and cook for 1 minute.

Remove the onion mixture from heat and let it cool slightly.

In a blender or food processor, combine the onion mix, toasted walnuts, cooked green beans, hard-boiled eggs, cooked brown lentils, mayonnaise, salt, and black pepper.

Grind the ingredients together well. If the mixture is too thick, add a few spoons of water or vegetable broth.

Taste and adjust salt and pepper as needed.

Chill the mixture for 4 hours to allow the flavors to develop.

Bring the spread to room temperature before serving.