Heat the olive oil in a large skillet over medium heat.
Drop in the garlic, pepper flakes, and a pinch of salt and stir frequently until the garlic turns golden and infuses the oil, about 2 to 4 minutes. Be careful not to let the garlic burn.
Add the broccolini to the skillet and cook, turning occasionally, for 2 to 3 minutes.
Pour in the water carefully--it will steam and may splatter--raise the heat to high, cover, and steam for 3 to 4 minutes.
Uncover the skillet and season with salt, if needed. Continue searing the broccolini until it's charred to your liking, 2 to 5 minutes.
Spritz some lemon juice over top and rush to the table.
Notes
Work in batches--If your broccolini won't fit comfortably in a single layer in the skillet, cook it in two batches.
Don't burn the garlic--Garlic is notorious for burning, which turns it bitter. If your slices start getting too dark, scoop them out and add them back to the pan later.
Storage and reheating--Store leftover broccolini in a sealed container in the fridge for up to 3 days. Reheat it in a warm skillet or an air fryer until crisped and heated through.
Dietary--This recipe is suitable for gluten-free diets.