Gather your equipment: a large crockpot, a cutting board, a sharp knife, and a wooden spoon for stirring.
Peel and chop the carrots into half-inch pieces, dice the celery stalks, and finely chop the onion. This creates colorful, evenly sized pieces that will cook uniformly and look appealing in the final dish.
Add the chopped carrots, celery, and onion into the crockpot, spreading them out evenly at the bottom. The layers help ensure all vegetables cook thoroughly and develop their flavors.
Pour in the vegetable broth, making sure it covers the vegetables comfortably. The broth will act as the cooking liquid, infusing the vegetables with savory flavor as they simmer.
Add the diced tomatoes along with their juices, then sprinkle in the dried thyme and place the bay leaves on top. These seasonings deepen the herbal aroma and add complexity to the soup’s flavor.
Cover the crockpot with its lid and set it to low. Let the soup cook gently for 6 to 8 hours, until the vegetables are tender and the flavors have melded into a fragrant, hearty broth.
Once the cooking time is up and the vegetables feel soft when pierced with a fork, stir in the frozen peas. Cover and cook on high for an additional 30 minutes to warm the peas and incorporate their sweet flavor.
Remove the bay leaves and taste the soup, adjusting salt and pepper as needed. Squeeze in a little lemon juice if you desire a bright, fresh finish.
Give the soup a gentle stir and let it rest for a few minutes to settle the flavors. The vegetables should be tender, and the broth flavorful and vibrant.
Serve the hot vegetable soup in bowls, garnished with fresh herbs if desired, for a comforting, nourishing meal full of color and texture.
