Peel and chop the carrots into thick slices or chunks, and dice the potatoes into bite-sized pieces. Trim the green beans and set aside. Gather all your ingredients and your crockpot.
Layer the carrots, potatoes, and green beans into the crockpot, creating an even bed for cooking. Pour in the crushed tomatoes and vegetable broth over the vegetables.
Add the fresh thyme sprigs and bay leaf on top, then drizzle with olive oil. Season generously with salt and pepper, adjusting to taste.
Cover the crockpot with the lid and set it to cook on low for 6 to 8 hours, or on high for 3 to 4 hours. As it cooks, fragrant steam will rise, and the vegetables will slowly soften.
After the cooking time, open the lid carefully. The vegetables should be tender when pierced with a fork, and the broth will have thickened slightly, looking rich and rustic.
Remove the thyme sprigs and bay leaf from the soup. Taste and adjust the seasoning with more salt and pepper if needed.
Optional: sprinkle chopped fresh parsley over the top for a burst of color and freshness. Drizzle a little extra olive oil for a glossy finish if desired.
Serve the hot soup in bowls, enjoying the fragrant aroma and hearty textures — tender vegetables in a thick, flavorful broth that looks inviting and rustic. Perfect with crusty bread or a simple side salad.