Fill a large pot with water, salt well, and set to boil for the pasta.
Add the olive oil to a large skillet or frying pan and heat on medium-high.
Peel and thinly slice the onion (don't chop) and add to the hot skillet or pan along with the chickpeas. Cook for five minutes, stirring as needed to prevent sticking.
Add pasta to boiling water and cook according to package instructions.
Add the cherry tomatoes, salt, and garlic to the pan, stir well and cook another five minutes, stirring as needed - it's fine if everything browns.
Add the harissa paste and coconut milk and stir. When at a lively simmer, cook for between five to eight minutes until at your desired consistency, stirring occasionally.
Drain the pasta when ready, reserving half a cup of cooking liquid.
Add the lemon juice and mix well. If desired, mash a few chickpeas and tomatoes with the back of a spoon to add more texture.
Add drained pasta to the pan and toss with the sauce until well-coated. Add some of the reserved pasta water little by little if needed to loosen the sauce.
Grind plenty of black pepper over the top (if using) and serve immediately. Enjoy.
