In a 4 quart or larger pot, add both the olive oil and minced garlic. Heat together over medium-high heat, stirring continuously. Once you hear the oil start to sizzle, stir for just an additional 30 seconds so the garlic is lightly cooked. Immediately remove from heat and transfer the oil / garlic mixture to a small bowl. Use a rubber spatula, if possible, to remove as much garlic and oil as you can. Set this mixture aside for now. In the same, unwashed pot, bring roughly 4 quarts of salted water to a boil over high heat. (I usually add about a tablespoon of salt to my pot of water, as this helps season the pasta.)
Once you achieve a rapid boil, add the broccoli floret to the pot to blanch and set a timer for three minutes. Afterwards, fish the florets out of the water with a slotted spoon and place in a separate bowl for now.
Allow the same pot of water to return to a boil, and then add the penne pasta. Reduce heat to medium-high and set your timer for ten minutes. Stir pasta occasionally to prevent it from sticking together. Carefully check the pasta for doneness at the ten minute mark. Cook for an additional 1-4 minutes, if needed.
Drain pasta and return it to the pot. Add the garlic/oil mixture, nutritional yeast, lemon zest, lemon juice, salt, pepper, and chili flakes and gently stir to evenly coat the pasta. Finally, gently fold in the blanched broccoli, as well.
Top with additional salt, pepper and chili flakes to taste!
Add fresh herbs or chopped nuts, if desired. See "Optional Add-Ins" section below for suggestions.
Serve immediately as a hot dish, at room temperature, or chill to serve later as a pasta salad. If you choose to serve chilled, allow the hot pasta to cool at least 20-30 minutes before transferring to an airtight container and storing in the fridge.