Bring a large pot of water to a rolling boil. Add the mafalda pasta and cook it for about 9-11 minutes or until it’s al dente (still slightly firm). Drain well and set aside so it’s ready when the rest is cooked.
While the pasta is cooking, heat your skillet over medium-high. Add the extra-lean ground beef, breaking it apart and cooking until it’s no longer pink. Then toss in diced onions and mushrooms; sauté until mushrooms release their water and onions soften.
Into that skillet, stir in the diced bell pepper and minced garlic. Let them cook just a minute until fragrant. Then season with salt & pepper and pour in the pasta sauce. Stir in the cooked pasta so everything is coated and warmed through.
Preheat your oven’s broiler on high. Dollop ricotta over the top of the lasagna mixture, and sprinkle shredded mozzarella evenly. Transfer the skillet to the oven and broil for about 1-2 minutes, watching carefully so the cheese melts and gets golden but doesn’t burn. Pull it out, garnish with fresh basil, and serve hot.