Place broccoli florets in a large skillet over medium heat. Mix water and 2 teaspoons lemon juice together in a small bowl; pour mixture over broccoli. Cover and steam until broccoli is bright green and tender, 10 to 15 minutes.
Meanwhile, melt butter in a small saucepan over medium-low heat; stir in garlic and salt. Reduce heat to low and sauté garlic until golden brown, about 8 minutes.
Drain cooked broccoli and return to skillet; sprinkle with remaining 2 teaspoons lemon juice; stir in garlic butter mixture. Sprinkle broccoli with black pepper and toss to combine.