Preheat your oven to 400 degrees Fahrenheit.

Prepare the vegetables by cutting them into uniform, bite-sized pieces.

Place the carrots, sweet potatoes, bell peppers, and red onions on a large baking sheet. Drizzle with olive oil and sprinkle with salt, pepper, and dried thyme. Toss to coat.

Spread the vegetables in a single layer and roast for 25 to 30 minutes until tender and slightly charred.

In a medium saucepan, cover the rinsed lentils with three cups of water or vegetable broth. Bring to a boil, then reduce to a simmer and cook for 20 to 25 minutes until tender but firm. Drain and set aside.

Prepare the dressing by whisking together the extra virgin olive oil, lemon juice, Dijon mustard, and minced garlic. Season with salt and pepper.

In a large mixing bowl, combine the cooked lentils and warm roasted vegetables. Add the baby spinach or arugula and toss gently.

Pour the dressing over the mixture and toss to combine. Transfer to a serving platter and top with crumbled feta cheese. Serve warm or at room temperature.