Preheat your oven to 200°C (410°F). It’s crucial to have it hot before you start preparing your packets; this helps cook everything evenly. While the oven heats, grab four sheets of aluminum foil, each about 16 inches by 12 inches. Fold up the edges to create shallow boats that will hold your delicious ingredients.
In a skillet, heat 2 tablespoons of olive oil over medium-high heat. Add the chopped onion and minced garlic. Stir them occasionally until they turn golden brown and fragrant, which should take about 3 to 4 minutes. This step is essential as it builds a flavorful base for your sauce.
Now, add the whole-grain mustard, honey, Dijon mustard, sweet paprika, and crushed red pepper flakes to the skillet. Stir the mixture together and cook for about 2 minutes until the sauce thickens slightly. You’ll want to transfer this flavorful concoction to a bowl and allow it to cool for a moment.
Next, take another bowl and toss the sliced zucchini and cherry tomatoes together with 2 teaspoons of salt and 3/4 teaspoon of ground black pepper. Drizzle with the remaining 2 tablespoons of olive oil and give it a good toss to coat the veggies evenly.
Pat the chicken breasts dry with paper towels and season them with a pinch of salt and ground black pepper. This often-overlooked step helps in achieving a nice sear and prevents the chicken from being watery.
Now, it’s time to assemble your foil packets. Divide the seasoned vegetables into four equal portions and place them on the center of each prepared foil sheet. Lay the seasoned chicken breasts on top of the vegetables, like the crown of a delicious meal.
Generously spoon the cooled honey mustard sauce over the chicken in each packet. Make sure it’s well coated; this is where the flavor really develops! Carefully fold the edges of the foil over the chicken and veggies, sealing the packets tightly, so they don’t leak.
Place the packets on a baking sheet and bake them in the preheated oven for about 20 minutes. During this time, the chicken will cook through while the vegetables become tender. You can check the internal temperature of the chicken using a meat thermometer; it should reach 73°C (165°F) for safety.
Once done, carefully open the foil packets to release the steam—be cautious, as it can be quite hot! Serve immediately, garnished with freshly chopped parsley if desired. The aroma will surely entice everyone to the table!