Prepare pasta according to package directions; drain and reserve 1/4 cup (60 mL) cooking liquid.
Meanwhile, heat oil in skillet set over medium heat; cook beans, onion, red pepper, garlic, chili powder, cumin, salt and pepper for 3 to 5 minutes or until vegetables are slightly softened. Stir in spinach; cook for about 1 minute or until starting to wilt.
Add pasta, reserved cooking liquid and diced tomatoes to skillet; cook for 2 to 3 minutes or until pasta is well coated and tomatoes are heated through.
Divide between 4 plates. Top with avocado and feta. Sprinkle with cilantro. Serve with lime wedges.
Tips
Transfer any leftovers to a large ramekin. Sprinkle with shredded Tex Mex cheese and bake until heated through and cheese is melted.