1 ounce olive oil
1/2 pound yellow onion, finely diced
1 head(or bulb) of fennel
3/4 pound dried lentils
2 quarts chicken or vegetable stock
1 small butternut squash, peeled and diced into 1/2" pieces
salt & pepper

Heat the oil in a stockpot, add the onions when oil is heated, and saute' until onions are soft but not colored. While this is occurring, clean the fennel, discarding the stems, and saving any feathery tops for garnish. Dice the trimmed fennel bulb into pieces same size as the chopped onion, and add to the cooking onions, sauteing all for several minutes. Wash and pick over the lentils, adding them to the pot. Continue to cook all together a few minutes, then add the stock to the lentils & vegetables.
Bring the soup to a boil, reduce to simmer, and cook gently until the lentils begin to break down, or about 20-30 minutes.

Add the diced squash to the soup, continuing to cook for another 8-10 minutes until squash softens, then season to taste with salt and pepper.
Spoon into bowls, garnishing with the chopped fennel tops.