In a soup pot heat the olive oil and cook the chopped bacon till the fat renders. Discard all but 2 tbsp of fat. To the same pot, add the chopped onion, carrots and celery and cook over low heat for 5-7 minutes. Once the vegetables softened a bit add the minced garlic, mushrooms and thyme, stir to combine and cook for 5 minutes longer.
Next bring in the lentils, bay leaves and the chicken stock to the pot and simmer for 20 minutes until the lentils are cooked through. Pour in the cream and add frozen spinach, cook for 5 minutes longer. Season with salt and pepper to taste.