Heat 1 tablespoon oil in a large pan and add chopped bell peppers. Saute on medium-high heat for 4-5 minutes or until the bell peppers are cooked but still crunchy. Transfer the sauteed bell peppers to a bowl and keep aside.
Cook pasta al dente following its package instructions. Once the pasta is cooked preserve around a cup of pasta water and then strain the pasta. Keep them aside.
Heat the remaining 1 tablespoon olive oil in the same pan in which bell peppers were sauteed. Add chopped onion and saute until it becomes translucent.
Add chopped garlic and saute for a few seconds.
Add red chili powder, cumin powder, ginger powder, and ground black pepper. Saute for around 30 seconds.
Add harissa paste and tomato paste. Saute for about a minute.
Next, add chopped tomatoes and salt. Cook on medium heat until the tomatoes are nicely cooked and turn mushy.
Add some pasta water to get a sauce like consistency and cook for 1-2 minutes.
Add cooked chickpeas, sauteed bell peppers, and sliced olives. Cook for a minute.
Finally, add cooked pasta and gently mix everything. Turn off the heat.
Add fresh lemon juice and chopped cilantro. Mix.