Begin by heating the olive oil in a spacious skillet over medium-low heat.
Season the chicken thighs with salt and pepper on both sides, then place them in the preheated skillet. Cook until the thighs are golden brown, no longer pink inside, and the juices run clear, about 8 to 10 minutes per side. An instant-read thermometer should register 165 degrees F (74 degrees C) when inserted into the thickest part. Remove the chicken and set it aside.
Lower the heat to a gentle simmer, adding the finely chopped onion and minced garlic to the skillet. Stir continuously until softened, which should take around 5 minutes. Pour in the white wine, using a wooden spoon to deglaze the pan, scraping up any browned bits. Allow the wine to reduce almost completely, for 3 to 5 minutes.
Incorporate the chopped sun-dried tomatoes, cooking for an additional minute. Stir in the chicken broth and Italian seasoning. Bring the mixture to a simmer and let it reduce slightly over the next 5 minutes. Add the fresh baby spinach, cooking until wilted, about 1 to 2 minutes.
Reduce the heat to low, then mix in the freshly grated Asiago cheese and heavy cream until the sauce is well blended. Add the lemon juice and season with additional salt and black pepper to taste.
Return the cooked chicken thighs to the skillet, allowing them to warm through for 5 to 7 minutes. Turn off the heat and let the pan sit while you prepare the pasta; the sauce will thicken as it cools.
Meanwhile, bring a large pot of lightly salted water to a rolling boil. Add the mini farfalle pasta, cooking it uncovered and stirring occasionally until it is al dente, approximately 7 to 8 minutes. Drain the pasta well.
To serve, divide the pasta among four bowls, placing a chicken thigh on top of each portion. Generously ladle the sauce over the pasta and chicken, ensuring each bowl is well coated. Enjoy this deliciously creamy Tuscan-inspired dish.