This, like bean and potato based soups, can be made ahead, but will thicken a lot. The best bet if you plan to make the soup in advance is to reheat heat it slowly adding water or stock as you need to restore the soup to its original thickness. And always check the seasoning of reheated soups before you serve them.
- 1 pound (about 2 medium heads) broccoli
- 1/3 cup extra virgin olive oil, plus more for serving the soup
- 2 medium Idaho potatoes, (about 1 pound), peeled and cut into 1/3 inch cubes
- 6 cloves garlic, peeled
- 10 cups hot water
- 3 bay leaves
- 1 pound brown or green lentils
- Freshly ground pepper
- 1/2 cup freshly grated Pecorino Romano cheese
Cut the florets from the broccoli stalks. Cut the florets into pieces about ½-inch. Trim the rough bottoms from the stalks, peel the stalks, and cut them into ½-inch dice.
Heat the oil in a deep, heavy 4-to 5 quart pot over medium heat. Add the potatoes and cook, stirring, until they are golden and begin to stick to the bottom of the pot. Don’t worry if they stick; the little brown bits will add lots of flavor to the soup. Whack the garlic with a flat side of a knife, stir into the garlic and cook a few minutes, stirring occasionally, until you can smell the garlic. Pour in the hot water and bring to a vigorous boil, stirring as you do to scrape up the browned bits of potato. Toss in the bay leaves and cook for 15 minutes. Stir in the lentils, reduce the heat to simmering and let simmer 15 minutes.
Stir in the broccoli, season the soup with salt and pepper, and cook until the broccoli and lentils are very tender, about 15 minutes. Skim any foam that rises to the surface as the soup simmers.
Remove the soup from the heat, pluck out the bay leaves, and let the soup rest of the heat, covered, 10 to 15 minutes. Ladle the soup into warm bowls and drizzle with olive oil. Pass the grated pecorino separately.