Lentil Apple Salad

INGREDIENTS:
1 1/4 cups (250 grams) uncooked lentils
2-3 apples
4 tablespoons (or to taste) of apple vinegar (or regular vinegar)
4 tablespoons (or to taste) of olive oil
Fresh tarragon (estragon) or crushed fennel seeds (to taste)
Salt and pepper (to taste)
Water for cooking (3 times the volume of lentils)