Heat the olive oil in a heavy-bottom skillet over medium heat. When the oil is hot, add the broccolini and garlic, and season with kosher salt and red pepper flakes to taste. Toss with tongs and cook uncovered for about 3 to 5 minutes to develop some color.
Reduce heat to medium-low and carefully pour in 1/4 cup water. Immediately cover with a lid and cook for about 3 to 5 more minutes, or until the broccoli is bright green and cooked through yet still slightly crunchy.
Remove from heat, season with a little more salt and sprinkle with parmesan cheese.
Serve with another drizzle of good olive oil and a squeeze of lemon.