Start by trimming any excess fat from the chicken thighs. Season both sides generously with kosher salt and freshly ground black pepper. This simple step enhances the flavor of the chicken and sets the stage for the dish.
Heat 1 tablespoon of olive oil in a 10-inch skillet over medium-high heat. Once hot, carefully add the seasoned chicken thighs. Be cautious not to overcrowd the skillet; you may need to cook in batches. Sauté for about 5 minutes on each side, or until they turn golden brown.
Once cooked, transfer the chicken to a platter and allow it to rest. This resting period is crucial as it helps the meat retain its juices.
In the same skillet, wipe out any residues with a paper towel to prepare for the sauce. Meanwhile, bring a large stock pot of water to a boil and season generously with kosher salt.
Add the penne pasta to the boiling water and cook according to the package directions, or until al dente. Remember to reserve some of the pasta cooking water for later!
About one minute before the pasta is done, add the broccoli florets to the boiling water. This will cook the broccoli just enough to keep it vibrant and tender.
Drain the pasta and broccoli in a colander, then transfer them to a large bowl. This will set the stage for combining everything later.
Next, melt the butter in the same skillet over medium heat. Once melted, add the minced garlic and stir for about 30 seconds until it becomes fragrant.
Now add the diced red bell pepper to the skillet and cook for an additional 3 to 4 minutes, until it starts to soften. This adds a sweet flavor to the dish.
Pour in 2 cups of the almond cashew milk, leaving ½ cup aside in a glass jar. Increase the heat to medium-high, cooking while stirring often until the milk reduces by one-third. This helps concentrate the flavors.
In the jar with the remaining almond milk, mix in the flour, cover tightly, and shake until well combined. This will help thicken the sauce beautifully.
Pour the flour mixture into the skillet, stirring to combine it with the almond milk mixture. Continue to cook until the sauce thickens enough to coat the back of a spoon.
Stir in the jar of basil pesto, mixing until fully incorporated. Adjust seasoning with kosher salt and freshly ground black pepper to taste.
Finally, pour the luscious sauce over the bowl of pasta and broccoli, tossing to coat everything evenly.
Slice the rested chicken thighs into strips and lay them over the pasta. Garnish with grated Parmesan cheese and fresh basil leaves if desired. Serve immediately and enjoy!
