Prepare the Roasted Vegetables: Preheat the oven to 400°F (200°C) and line a large baking sheet with parchment paper. In a large bowl, toss the potato wedges and halved Brussels sprouts with olive oil, minced garlic, grated Parmesan, salt, and black pepper until evenly coated. Spread in a single layer on the prepared sheet, ensuring the pieces are not overcrowded. Roast for 30–35 minutes, flipping halfway through, until the potatoes are golden and the Brussels sprouts are caramelized and crisp at the edges.
Marinate and Cook the Chicken: While the vegetables roast, combine the chicken thighs with olive oil, minced garlic, dried herbs, lemon zest, lemon juice, salt, and pepper in a bowl. Allow the chicken to marinate for at least 15 minutes. Heat a skillet or grill pan over medium-high heat and cook the chicken thighs for approximately 6–8 minutes per side, until golden brown and cooked through (internal temperature 165°F / 74°C). Remove from heat and slice into bite-sized pieces.
Prepare the Spicy Feta Whip: In a food processor, combine the crumbled feta cheese, Greek yogurt, red pepper flakes, lemon juice, and olive oil. Blend until completely smooth and creamy, pausing to scrape down the sides as needed. The mixture should be thick, tangy, and luxuriously whipped. Set aside.
Create the Alfredo Sauce: In a large saucepan, melt the butter over medium heat. Add the minced garlic and sauté briefly until fragrant but not browned. Pour in the heavy cream, stirring occasionally, and bring to a gentle simmer. Gradually whisk in the grated Parmesan cheese until melted and smooth, creating a velvety sauce. Season to taste with salt and freshly cracked black pepper, then reduce the heat to low to keep warm.
Make the Basil Oil: In a small blender or food processor, blend the fresh basil leaves with olive oil until smooth. For a refined presentation, strain through a fine-mesh sieve for a clear green oil, or leave it rustic for a thicker drizzle.
Assemble the Dish: Add the sliced lemon-herb chicken to the warm Alfredo sauce, gently folding it in until the pieces are evenly coated. Spoon small dollops of the spicy feta whip into the sauce, swirling gently with a spoon to create a marbled effect. Arrange the roasted Brussels sprouts and potato wedges on serving plates or shallow bowls. Generously spoon the creamy chicken Alfredo mixture over the top.
Finish and Serve: Drizzle each portion with basil oil and sprinkle with extra cracked black pepper. Serve immediately for best texture and flavor, and enjoy this bold, creamy, and irresistibly zesty Lemon-Herb Chicken Alfredo with Spicy Feta & Crispy Brussels-Parmesan Wedges.