An adaptation of a Cook’s Illustrated recipe that I found on

4 bone-in, skin-on chicken thighs, trimmed of excess fat and skin
Good Salt and Freshly Ground Pepper
1 TB Olive Oil
1 cup Onion, halved and sliced about 1/4 inch thick OR if you have roasted any of the cippolini onions use those
2 tsp Tomato Paste
1 - 2 cloves Garlic, minced
1/2 tsp Anchovy Paste
1 cup Eatwell Farm Chicken Stock
1 cup of your Roasted Tomatoes, or use them fresh, diced and cooked a bit beforehand
1/4 cup Dry Red Wine
Pinch of Red Pepper Flakes
1 tsp dried Thyme
1 Bay Leaf
1 bunch of Chard
1/2 cup Balsamic Vinegar

Adjust oven rack to lower-middle position; heat oven to 350 F.  Sprinkle both sides of chicken thighs with salt and pepper.  Heat oil in an oven proof, lidded skillet over medium-high heat until shimmering; add chicken thighs skin-side down and cook without moving them until skin is crisped and well browned, 10 to 12 minutes.  Using tongs, turn chicken and brown on second side, about 5 minutes longer. Transfer to a large plate.  Pour off all but 1 tsp fat from pot.  Add the onion and tomato paste and cook over medium heat, stirring occasionally and scraping bottom of pot with wooden spoon, until tomato paste begins to darken, about 3-4 minutes (if bottom of pot becomes very dark and sticky, stir in 1 to 2 TB of water).  Add garlic and anchovy and cook, stirring constantly, until fragrant, about 1 minute.  Stir in tomatoes, chicken broth, and wine, scraping up browned bits with wooden spoon.  Add red pepper flakes, thyme and bay.  Remove and discard skin from chicken thighs, then submerge chicken bone-side up in liquid, adding any chicken juices accumulated on plate.  Increase heat to high, bring to simmer, cover, then place pot in oven.  Cook until chicken offers no resistance when poked with tip of paring knife but meat still clings to bone, 40 to 55 minutes.  While chicken cooks, trim bottom off the chard stems, then stems from leaves.  Roughly chop the leaves, but chop the stems small.  Also while chicken cooks, simmer balsamic vinegar in a small saucepan over medium heat until thick, syrupy and reduced to about 1/4 cup, 3 minutes.  Set aside.  Using a slotted spoon, transfer chicken to plate and tent with foil; discard bay leaf.  Bring liquid in skillet to simmer over medium-high heat.  Add chard and cook until stems are soft and leaves are wilted, about 2 minutes.  Stir about 1/2 the sauce into the balsamic reduction to loosen, then stir that mixture back into the sauce.  Taste and adjust seasoning with salt and pepper.  Return the chicken and any accumulated juices to sauce, cook until through, about 2 minutes, turning chicken once or twice.  Use a slotted spoon to transfer chard to serving dish or individual bowls; place chicken thighs on chard, then spoon sauce over.  Serve immediately.