Cook the pasta. In a large pot of boiling salted water, cook 500g pasta, stirring occasionally, according to package directions. Drain, reserving 470ml (2 cups) pasta cooking liquid.
500 grams medium tube pasta such as: rigatoni
Sauté the onion. Heat 1 Tbsp oil in the same pot over medium-high heat. Add the finely chopped onion and cook, stirring occasionally with a wooden spoon, until softened, about 6–8 minutes.
1 medium onion, 1 Tablespoon Olive oil
Add spices and tomato paste. Stir in tomato paste, freshly ground black pepper, red pepper flakes, and smoked sweet paprika. Cook, stirring occasionally, until the onion is coated and the paste slightly darkens in color, about 5 minutes.
2 Tablespoons tomato paste, 2 teaspoons smoked sweet paprika, ¼ teaspoon freshly ground black pepper, 1 teaspoon crushed red pepper flakes
Add roasted red peppers and garlic. Add finely chopped roasted red peppers, the minced garlic cloves, and salt. Stir often until any liquid is evaporated and the vegetables are combined and glossy-looking, about 5 minutes.
6 cloves garlic, 4 whole roasted red peppers from a jar, 1 teaspoon salt
Make the sauce. Remove the sauce base from the heat and add the reserved pasta cooking liquid (you may not need all of it), lemon zest, and fresh lemon juice. Add the rinsed white beans. Use an immersion blender to blitz the sauce, or transfer to a high-speed blender (like a Vitamix) for the smoothest consistency.
1 450 grams can white beans, 470 millilitres pasta cooking liquid, 1 Tablespoon fresh lemon juice, 2 teaspoon finely grated lemon zest
Heat and thicken. If using a stand blender, return the sauce to the pot. Reduce heat to medium and stir until the sauce is heated through and thickened, about 3–5 minutes.
Combine with pasta. Remove from heat and immediately add the cooked pasta. Toss to coat the pasta in the sauce.
Serve. Divide the pasta among bowls. Drizzle with a little oil (optional), spoon breadcrumbs on top, and squeeze fresh lemon juice over if desired. Serve with lemon wedges.
2 Tablespoon Chopped fresh parsley