Bring a large covered pot of salted water to boil.
Meanwhile, trim the broccoli: Trim base and discard. Cut the florets off the top, and into about 1 inch (2½cm) pieces. Pull off all the better leaves and add to the florets. If using the stalk, which will make the sauce creamier when mashed, peel or cut off the tough outer layer, and slice into as thin of rounds possible.
Place the garlic, chili pepper and about 1 Tablespoon of olive oil in a sauté pan or skillet, and cook for a few minutes over medium heat until the garlic just starts to color. Careful not to let it brown. Pour in1 cup (240ml) of water, and bring to a boil.
Add the broccoli and ¼ teaspoon of salt. Optionally add lemon zest. Cover and cook over medium heat until just tender and most of the water has evaporated.
Meanwhile, add the pasta to the salted boiling water and cook, stirring occasionally, until al dente, tender yet still firm to the bite.
Mash half of the broccoli in the pan into a paste with a potato masher, making sure to mash all of the creamy slices of stalk, if using. Add 4 tablespoons of olive oil and mix well. Taste and adjust for salt. Cover to keep warm until pasta is ready.
Transfer the pasta to the broccoli with a pasta fork and toss. Enjoy immediately!
Sausage Variation: After mashing the broccoli, add 6oz of cooked ground or link sausage, roughly broken or cut into bite-size pieces (or pre-cubed pancetta; or bacon, cut into 1/4" (6mm) lardons).Broccoli Substitutions: This recipe is delicious made with broccolini, purple broccoli, broccoli rabe, Romanesco broccoli and cauliflower. (Olives are a delicious addition if using Romanesco or cauliflower.)