In a medium saucepan, melt 1 tablespoon of butter over medium heat. Stir in 2 tablespoons of flour and cook, stirring continuously, for approximately 2 minutes to remove the raw flour taste. Gradually add ¾ cup of hot milk, whisking constantly to ensure a smooth consistency. Continue to stir until the sauce thickens slightly. Remove from heat and set aside, ensuring it remains warm when incorporating it into the scampi sauce.

In a large skillet, melt 3 tablespoons of butter over low heat. Add 2 tablespoons of crushed garlic, ½ teaspoon of crushed red pepper flakes, 2 teaspoons of Italian seasoning, and a pinch of black pepper. Stir and allow the ingredients to cook for approximately 2 minutes, ensuring that the garlic becomes aromatic but does not brown.

Pour in ¾ cup of white wine and 1 cup of chicken broth, stirring well to combine. Allow the sauce to simmer for 30 to 40 minutes, stirring occasionally, to reduce slightly and enhance the flavors. Once reduced, incorporate ¼ cup of the prepared white sauce, stirring until fully blended. Continue to cook until the sauce achieves a slightly thickened consistency. Remove from heat and set aside.

Preheat the oven to 350°F (175°C). Separate a head of garlic into individual cloves, leaving the peels intact. Toss the cloves in a small amount of olive oil and place them in aluminum foil or a covered baking dish. Roast for approximately 30 minutes, or until the cloves become soft and caramelized. Once cooled, squeeze each clove gently to extract the softened garlic from the peel. Set aside for later use.

Using a meat mallet, flatten 2 chicken breasts to ensure even cooking. Lightly coat them with flour for a subtle crust. Heat a small amount of olive oil in a large skillet over medium-high heat. Sear the chicken for 3 to 4 minutes per side, or until golden brown and nearly cooked through.

Add sliced bell peppers and red onion to the pan, sautéing them alongside the chicken. Continue to cook for an additional 4 to 5 minutes, or until the vegetables become tender and the chicken is fully cooked. Finally, add the roasted garlic cloves to the pan and stir gently to incorporate.

Reduce the heat to low and pour the prepared scampi sauce over the chicken and vegetables, ensuring everything is evenly coated. Allow the mixture to simmer gently for 2 to 3 minutes, enabling the flavors to blend.

Serve the chicken and sauce over a bed of cooked angel hair pasta, ensuring each serving is well-coated with the scampi sauce. Garnish as desired and serve immediately.