In a large pot over medium-high heat, add olive oil. Add the chopped onion, celery, and diced carrot, and sauté. Then add the diced potatoes and butternut squash.

Season with salt, pepper, and thyme.

Add about 4 cups water (about 1 liter), just enough to cover the ingredients. You can add a chicken bouillon cube or 4 cups chicken broth instead of water. Toward the end, I sometimes add a small piece of leftover cooked pork for extra flavor. Let everything simmer until tender.