In a pot, bring 1 1/4 cups water to a boil. Add lentils, spring onions, salt, and pepper. Reduce heat and let simmer until lentils are tender and water has been absorbed, 22 to 25 minutes. If lentils are not tender but water has been absorbed, add 1/4 cup of water and continue to cook. When lentils are done, stir in fresh marjoram.
Place arugula on a platter or in a bowl and sprinkle with cooked lentils, goat cheese, and almonds.
In a jar with a tight-fighting lid, shake together ingredients for the dressing and pour over salad to serve.