Prep Ingredients: Pat the chicken dry and season with salt and pepper and chill until ready to use. Cut the pancetta or bacon into strips. Peel the onions. Add the black garlic to a food processor and pulse until puréed. Mince the tarragon.
Brown the Pancetta: Place the pancetta in a large, oven-proof skillet and turn the heat to medium high. Cook for 5-7 minutes until the fat has rendered and the pancetta is crispy. Transfer the pancetta to a bowl.
Add the cipollini onions to the skillet with a small drizzle of olive oil and season with salt and pepper. Cook, turning regularly until browned, about 10-12 minutes. Add the black garlic and cook until fragrant, an additional 2-3 minutes. Transfer the black garlic and onions to the bowl with the pancetta.
Make the Chicken: While the onions are cooking, add the flour to a large, shallow bowl and season with salt and pepper. Dredge the chicken in flour and shake off the excess. Add the remaining olive oil the skillet you cooked the onions in and turn the heat to medium high. Add the chicken, skin side down, and cook for 8-10 minutes or until well-browned. Flip and cook an additional 5 minutes. Arrange the onions, pancetta, and black garlic around the chicken and add the wine and stock. Avoid covering the chicken with liquid. Your liquid should over about half of the chicken, while keeping the skin exposed. Bring to a boil and then transfer to the oven. Cook for 30-40 minutes or until a thermometer inserted into the chicken reads 165ºF.
Finish the Sauce: Transfer the chicken to a serving platter and return the skillet to the stove. Bring the sauce to a boil for 5-7 minutes or until reduced slightly. Add the peas, heavy cream, and tarragon and cook for 5 minutes. Remove from heat.
To Serve: Divide a few spoonfuls of sauce between bowls and top with microgreens. Place a piece of chicken on top and serve with crusty bread. Enjoy!