Cook pasta according to package directions and drain.
While pasta is cooking, heat oil in a large pot over medium heat and sauté the garlic, red pepper, and asparagus.
Add the broth and bring to a boil; simmer until vegetables begin to soften.
Add the basil, salt, pepper, butter, and cooked chicken. Cook until chicken is heated through.
Add cooked, drained pasta, Parmesan cheese, and pecans. Mix thoroughly and serve immediately.
Before chopping the asparagus, prepare it by rinsing it under running water, then holding it with both hands and snapping off the tough end. Hold the stalk so that the hand on the tip end is closer to the center of the stalk and the hand on the cut end is close to the end of the stalk. Bring your hands down and toward each other, and the stalk will snap just where it starts to get tough at the end.
To easily chop fresh basil, roll the leaves up together and slice starting at one end of the roll and working your way across. For smaller pieces, continue by chopping crosswise.
Vegetarian optionSubstitute vegetable broth for the chicken broth. You can either simply omit the chicken altogether, increasing the amount of asparagus and red pepper, or substitute a can of rinsed cannellini beans for the chicken.