Heat the oil in a large frying pan over a medium heat until it shimmers.
Add the garlic and cook for 30 seconds to 1 minute, until fragrant and just starting to turn golden.
Tip in the spinach and toss with tongs until it’s wilted, about 2–4 minutes.
Remove the pan from the heat, then stir in the mint leaves and lemon juice.
Season with salt and pepper to taste and adjust if needed.