Pre-heat the oven to 375ºF.
Mix the tomatoes, onions and garlic with 1/2 tablespoon of olive oil and a sprinkle of salt and pepper. Arrange on a baking sheet. Mix the carrots and butternut squash with 1/2 tablespoon of olive oil and a ¼ teaspoon of salt and freshly ground pepper and arrange it right next to the other vegetables on the sheet pan. Spread thyme and rosemary sprigs over vegetables. Roast for 30-40 minutes. Make sure to stir the vegetables once or twice, but don’t mix the tomatoes with the carrots and butternut squash. Remove from the oven. Discard herbs.
Add the tomatoes, garlic and onions to a food processor and process until smooth.
Remove carrots and butternut squash into a bowl. If there are caramelized bits in the baking sheet, deglaze the pan with some broth.
Put the tomatoes, garlic and onion mixture in a large pot and bring it to a boil, add dried thyme and basil (or any dried herbs you wish), add the lentils and stir. Add the broth and bring it to a boil. Let simmer for about 30 minutes. Test for salt and add more if necessary.
Add the spinach, roasted carrots and butternut squash.
Simmer for 5 to 10 minutes and serve.