Melt the butter in a large frying pan over high heat until foaming. Add the zucchini, squash and peas, and cook, stirring occasionally, for 5 minutes or until vegetables are just tender.
Add the garlic, lemon juice and lemon thyme, and cook, stirring, for 1 minute or until fragrant. Remove from heat. Taste and season with pepper. Place in a large serving bowl and sprinkle with Sea Salt Flakes.