Heat olive oil in a large skillet over medium-low heat.
Season both sides of chicken thighs with salt and pepper. Place seasoned chicken into hot skillet; cook until golden and thighs are no longer pink in the center, and the juices run clear, 8 to 10 minutes per side. An instant-read thermometer inserted near the center should read 165 degrees F (74 degrees C). Remove chicken thighs from pan; set aside.
Reduce heat to low; add onion and garlic to skillet. Cook and stir until softened, about 5 minutes. Pour in white wine and use a wooden spoon to scrape up any browned bits from the bottom of the pan. Cook until wine is almost evaporated, 3 to 5 minutes.
Add in sundried tomatoes and cook for 1 minute. Stir in chicken broth and Italian seasoning. Bring to a simmer, and cook until mixture has slightly reduced, about 5 minutes. Add spinach to skillet and cook until wilted, 1 to 2 minutes.
Reduce heat to low; stir in Asiago and heavy cream until well combined. Stir in lemon juice. Season to taste with salt and ground black pepper.
Return chicken thighs to skillet; heat until warm, 5 to 7 minutes. Turn off heat; allow pan to sit off heat while cooking the pasta. Sauce will thicken as it cools.
Meanwhile, fill a large pot with lightly salted water and bring to a rolling boil. Stir in mini farfalle; return to a boil. Cook pasta uncovered, stirring occasionally, until tender yet firm to the bite, 7 to 8 minutes; drain.
Divide pasta between four bowls, and top each with chicken thighs and sauce to serve.
