For the dip: Mix the mayonnaise, garlic, lemon juice and plenty of freshly ground black pepper in a small bowl until well combined. Refrigerate until ready to use.
For the broccoli tots: Bring a large pot of generously salted water to a boil. Prepare a bowl of ice water.
Add the broccoli florets and stems to the boiling water and cook until a very vibrant green and lightly softened, 1 to 2 minutes. Drain the broccoli and immediately submerge into the bowl of ice water to stop the cooking. You want the broccoli to remain as green as possible. Squeeze the broccoli in clean dish towels to remove as much of the water as possible.
Add the broccoli to the bowl of a food processor and pulse a few times until finely chopped. Add the parsley, chives, lemon zest and juice, garlic and onion and pulse until the mixture is well combined and no large chunks of any ingredient remain (you should have about 3 1/2 cups of the broccoli mixture). Transfer to a large bowl and add the breadcrumbs, egg, red pepper flakes, 2 teaspoons salt and a generous amount of freshly ground black pepper and mix to combine. You want the mixture to hold together when formed into a ball.
Using a tablespoon as a guide, scoop the mixture from the bowl, roll into balls (each ball should weigh about 21 grams) and place on a baking sheet. Repeat with the remaining broccoli mixture (you should have about 28 tots). Place the baking sheet in the freezer for 20 minutes.
Meanwhile, fill a pot with vegetable oil so it comes about 2 inches up the sides. Fit the pot with a deep-fry thermometer and heat the oil over medium-high heat to 375 degrees F.
Fry the tots in 2 to 3 batches until the outsides are a deep golden brown, the insides are still very green and the tots are warmed throughout, 2 to 3 minutes (be sure not to overcrowd the pot or the oil will drop too dramatically in temperature and the outside of the tots will not be crispy). Use a slotted spoon to transfer the tots to a paper towel-lined plate. Sprinkle with salt. Be sure to bring your oil back to temperature between each batch. Serve immediately with the dip.