Place a large skillet in the oven and preheat the oven to 325°F.
Place the olive oil in a large skillet over high heat.
Add the onions and cook, stirring frequently, for about 10 minutes, until the onions begin to brown. Adjust the heat so that the onions don’t burn.
Add the vinegar and vegetable broth and stir.
Cover, reduce the heat to medium, and simmer for 7 minutes. Stir occasionally. Uncover and continue cooking until the mixture is very thick (about 10 minutes). Watch the onions carefully so that they don’t burn – there should still be some liquid in the onions to make a sauce for the pasta.
While the onions are cooking, place the water in a large sauce pan over high heat. When the water boils, add the pasta.
Cook, stirring occasionally, for about 15 minutes (or according to package directions) until the pasta is tender, but not mushy.
Drain and place in a large mixing bowl.
While the onions are cooking, add the chicken thighs to the skillet in the oven.
Roast for about 12 to 15 minutes. Remove the chicken to a plate and let cool for 5 minutes.
When the onions are done, add them to the bowl with the pasta and gently fold together.
Cut the cooked chicken thighs in 1/2 inch cubes, add to the bowl with the pasta, then gently fold together. Chill for at least 1 hour.
Just before serving, add the red pepper, pine nuts, pepper, salt, and blue cheese to the bowl.
Fold together gently and serve.