• Preheat the oven to 375°.
• Use a sharp knife to poke 6 to 8 holes through each spaghetti squash. 
• Place the squashes on a baking sheet and bake until easily pierced with a knife, 1 hour to 1 hour and 20 minutes.
• While the squashes bake, place the lentils in a small saucepan and cover them with water.
• Place the saucepan over high heat and bring the water to a boil.
• Lower the heat and allow the lentils to cook just until tender, 20-25 minutes.
• Drain the lentils into a colander and then return them to the pot. Set it aside.
• When the spaghetti squashes are finished baking, remove them from the oven and allow them to cool.
• While the squashes cool, coat the bottom of a large skillet with olive oil. Add the onion and sauté until soft and translucent, about 5 minutes.
• Add the garlic and sauté until very fragrant, about 1 minute more.
• Stir in the cooked lentils, diced tomatoes, tomato sauce, cumin, ancho chile powder and paprika.
• Raise the heat and bring the mixture to a simmer. Lower the heat and allow it to simmer for 5 minutes.
• Remove the pan from the heat and season with salt and pepper to taste.

To Make the Guacamole

• Place the avocadoes into a small bowl and mash them with a fork.
• Stir in the lime juice, tomato, onion, cilantro and garlic. Season with salt and pepper to taste.

To Make the Stuffed Spaghetti Squash

• When the squashes are cool enough to handle, cut them in half lengthwise with a sharp knife.
• Scoop out the seeds from the squash with a spoon, then take a fork and rake the inner flesh to create a stringy texture.
• Stuff the squash halves with the lentil mixture, then top with guacamole and toppings of choice.
• Serve.