Step 1

Preheat the oven to 375 degrees F. Cut spaghetti squash in half lengthwise. Season with a pinch of salt and pepper and a drizzle of olive oil. Place cut side up on a large rimmed baking sheet, and bake 35-45 minutes, until tender. Cool. Use two forks to scratch up the squash to create "noodles" inside the squash "boats."

Step 2

Meanwhile, make the lentil bolognese. Heat two tablespoons of olive oil in a skillet over medium heat. Add the onions, carrots, and celery and sauté until vegetables soften, about 7 minutes. Add the garlic, mushrooms, oregano, basil, and red pepper flakes, and sauté until the mushrooms begin to soften. Add the tomatoes and tomato paste and stir to combine. Add lentils and simmer the sauce 20 minutes, until sauce has thickened and all the vegetables are tender. Season to taste with salt.

Step 3

Spoon the lentil bolognese over the spaghetti squash noodles. Sprinkle cheese over the top and place under the broiler until cheese is bubbly. Garnish with fresh basil.