Start by seasoning the boneless skinless chicken thighs generously with kosher salt and pepper. In a large skillet, melt 1 tablespoon of unsalted butter over medium-high heat. Once the butter is bubbling, add the chicken thighs and brown them for 3–4 minutes on each side until golden brown. Remove the chicken from the skillet and set it aside.

In the same skillet, add the remaining tablespoon of butter and lower the heat to medium. Once melted, toss in the diced shallots and halved cremini mushrooms. Sauté for 3–4 minutes until soft and the mushrooms have released their moisture. Add the minced garlic and fresh thyme, stirring for another minute until fragrant.

Sprinkle 2 tablespoons of all-purpose flour over the sautéed vegetables, stirring constantly for about 1 minute. Gradually pour in 3 cups of chicken stock while scraping the bottom. Stir in 1½ teaspoons of Dijon mustard, bring to a gentle simmer, and thicken slightly for about 2-3 minutes.

Stir in 1 cup of orzo, ensuring it’s evenly distributed in the sauce. Nestle the browned chicken thighs back into the skillet, cover with a lid, and let simmer for about 8–10 minutes. Stir occasionally, cooking until the orzo is tender and chicken is fully cooked, reaching an internal temperature of 165°F.

Once the orzo is al dente, add 4 cups of baby spinach and stir until just wilted, which should take about 1-2 minutes. Reduce heat to low and stir in ¼ cup of heavy cream and ⅓ cup of freshly grated Parmesan cheese until smooth and creamy. Remove from heat and garnish with chopped fresh parsley.