Heat a large skillet over medium heat and add the olive oil, allowing it to shimmer.
Add the minced garlic to the hot oil and sauté for about 30 seconds until fragrant, listening for a gentle sizzle and noting the garlic turning slightly golden.
Add the sliced zucchini and yellow squash to the skillet, spreading them out evenly in a single layer.
Sauté the vegetables for about 4-5 minutes, flipping occasionally, until they start to soften and develop light caramelization around the edges, and their color remains bright.
Sprinkle in the chopped thyme, then season with salt and black pepper to taste, stirring to evenly distribute the herbs.
Cook for another 1-2 minutes, allowing the flavors to meld and the vegetables to gain a slight crispy edge while remaining tender-crisp to the bite.
Remove from heat and transfer the stir-fried squash to a serving dish, ready to enjoy as a bright, crunchy vegetable side.