Cook pasta al dente (in salted water and firm when taken off the heat) according to package instructions. Reserve 1 cup of pasta water.
Heat 1 tbsp of olive oil in a saucepan over medium heat. Add minced garlic cloves and red bell pepper. Stir occasionally until the bell pepper is cooked (about 5 minutes).
Process all ingredients for the pesto: sun-dried tomatoes, basil, walnuts, red chili flakes, black pepper, and bell pepper, garlic, and olive oil from the previous step.
Add ¼ cup sliced olives and some more sun-dried tomatoes (I used ~ 2 tbsp but this is up to you!) to the same saucepan used for the bell pepper earlier. Then add ½ cup pasta water to the saucepan. Add ¾ cup pesto (~ half of it) to the water and mix until it forms a creamy sauce. Add more pesto and/or pasta water if necessary. Stir in the pasta and lower heat to medium-low. If using, add the handful of spinach now. It will wilt in the heat of the pasta. Stir the pasta together for a couple minutes before taking it off the heat.
Stir in the pasta and lower heat to medium-low. If using, add the handful of spinach now. It will wilt in the heat of the pasta. Stir the pasta together for a couple minutes before taking it off the heat. Top it with red chili flakes, basil, and a squeeze of lemon juice!
