Heat the olive oil in a large pot over medium heat.
Add the ground turkey and cook until browned, breaking it into small crumbles with a wooden spoon.
Stir in the diced onion, carrots, and celery, sautéing for 5 minutes until the vegetables begin to soften.
Add the minced garlic, dried thyme, sea salt, and black pepper, stirring for 1 minute until aromatic.
Rinse the dry lentils and add them to the pot along with the vegetable broth.
Bring the soup to a boil, then reduce the heat to low and cover with a lid.
Simmer for 20 to 25 minutes, or until the lentils are tender but not mushy.
Turn off the heat and stir in the fresh baby spinach until it is just wilted.
Adjust seasoning if necessary and serve hot.