Heat the oven to 425°F. Toss the butternut squash with 1 tbsp olive oil, garlic, thyme, salt, and pepper. Roast for 25-30 mins or until tender.
In a large pot, combine lentils, 6 cups water and bring to a boil over high heat. Reduce heat to low and simmer for 20 to 30 minutes, until lentils are tender.
In a small bowl, whisk together vinaigrette ingredients. .
While the lentils are still warm, toss them with the vinaigrette. Add the roasted squash and onions and toss until well coated. Taste and season with salt and pepper as needed.
If desired, sprinkle with pecans, pumpkin seeds, and/or dried cranberries before serving.