Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Toss the broccoli florets and sliced red bell pepper with half of the olive oil, sea salt, and black pepper.
Spread the vegetables in a single layer and roast for 18 minutes until the edges are golden and tender.
Boil the whole grain penne pasta according to package instructions until al dente, then drain.
Season the chicken breast with a pinch of salt and pepper on both sides.
Heat the remaining olive oil in a large skillet over medium-high heat.
Sear the chicken for 6 minutes per side until golden and the internal temperature reaches 165°F (74°C).
Transfer the chicken to a cutting board, let it rest for 3 minutes, and slice into thin strips.
In the same skillet, add the minced garlic and red pepper flakes, sautéing for 1 minute until fragrant.
Add the cooked pasta, roasted vegetables, and sliced chicken to the skillet, tossing with fresh lemon juice before serving on a plate.