Stovetop Chicken Tetrazzini

Place an oven rack in the center of the oven, then preheat to 450°F. Heat a large pot of salted water to boiling on high. Wash and dry the fresh produce. Cut off and discard the bottom 1/2 inch of the broccoli stem; cut the broccoli into large florets. Thinly slice the mushrooms. Peel and roughly chop the garlic. Cut out and discard the stem, ribs, and seeds of the pepper, then medium dice. Pick the oregano leaves off the stems; discard the stems and roughly chop the leaves. Roughly chop the walnuts. 

Line a sheet pan with aluminum foil. Place the broccoli florets on the foil. Drizzle with olive oil and season with salt and pepper; toss to coat. Arrange in an even layer. Roast 20 to 22 minutes, or until browned and tender when pierced with a fork. Remove from the oven. Evenly top with half the vinegar (you will have extra) and a drizzle of olive oil. Carefully stir to coat; season with salt and pepper to taste. 

While the broccoli roasts, pat the chicken dry with paper towels; season with salt and pepper. In a large pan, heat 2 teaspoons of olive oil on medium-high until hot. Add the seasoned chicken in an even layer and cook, without stirring, 3 to 4 minutes, or until lightly browned. Continue to cook, stirring frequently, 3 to 4 minutes, or until browned and cooked through. Leaving any browned bits (or fond) in the pan, transfer to a plate. 

While the broccoli continues to roast, to the pan of reserved fond, add the sliced mushrooms in an even layer (if the pan seems dry, add a drizzle of olive oil). Cook on medium-high, without stirring, 2 to 3 minutes, or until lightly browned. Add the chopped garlic and diced pepper; season with salt and pepper. Cook, stirring frequently, 3 to 4 minutes, or until slightly softened. Add the demi-glace, 1/4 cup of water (carefully, as the liquid may splatter), and half the chopped oregano; season with salt and pepper. Cook, stirring occasionally and scraping up any fond, 1 to 2 minutes, or until the vegetables are softened and the liquid is slightly reduced. Turn off the heat; season with salt and pepper to taste. 

While the vegetables cook, add the pasta to the pot of boiling water; cook 3 to 4 minutes, or until al dente (still slightly firm to the bite.) Turn off the heat. Reserving 3/4 cup of the pasta cooking water, drain thoroughly and return to the pot.

To the pot of cooked pasta, add the cooked chicken, cooked vegetables, butter, mascarpone cheese, goat cheese, and half the reserved pasta cooking water. Cook on medium-high, stirring vigorously, 1 to 2 minutes, or until coated. If the pasta seems dry, gradually add the remaining cooking water to achieve your desired consistency. Season with salt and pepper to taste. Garnish the finished pasta with the remaining chopped oregano and half the parmesan cheese. Garnish the roasted broccoli with the chopped walnuts and remaining parmesan cheese. Enjoy!