Chuck the linguini in the microwave for 10 minutes in boiling salted water.
Fry the carrots and onions on high heat, stirring constantly, until starting to brown and caramelize. Add the garlic, bacon/meat, harissa, tomato paste and fry for another 2 minutes. Add the tahini and the pasta back to the pan (pasta should be done by now, drain the water) and stir well to combine. Mix through the yoghurt, taste and season with salt and pepper if necessary. Serve with a squeeze of fresh lemon juice.