Gather all your vegetables and chop the carrots, celery, and onion into bite-sized pieces, creating a colorful, fresh prep station.
Place your slow cooker on the counter and add the chopped carrots, celery, and onion along with the diced potatoes and canned tomatoes, creating a vibrant mixture.
Pour in the vegetable broth, ensuring all the ingredients are submerged. Stir gently to combine, releasing a savory aroma as the vegetables start to mingle.
Drop in the thyme and bay leaf, then cover the slow cooker with its lid. Set it to low and let it cook for 6 to 8 hours, filling your kitchen with a warm, inviting scent.
After the cooking time, check that the vegetables are tender and easily pierced with a fork. If you prefer a smoother texture, carefully use an immersion blender to puree part of the soup directly in the cooker.
Remove the bay leaf and thyme sprigs. Taste the broth and season with additional salt or herbs if needed, adjusting for your preferred flavor balance.
Use a soup ladle to serve the hot, hearty soup into bowls, revealing a rustic mixture of soft, colorful vegetables and a fragrant, savory broth.
Finish with a sprinkle of fresh herbs or a drizzle of olive oil for added brightness. Enjoy your comforting, homemade vegetable soup on a busy night or when you need a cozy meal.