Preheat the oven to 400 degrees Fahrenheit. Toss the quartered baby potatoes with 1 tablespoon of olive oil, salt, and pepper. Spread on a baking sheet and roast for 25-30 minutes until golden and fork-tender.
Season the chicken breasts generously with salt and pepper on both sides.
Heat the remaining 1 tablespoon of olive oil in a large skillet over medium-high heat. Add the chicken and sear for 5-6 minutes per side, or until golden brown and the internal temperature reaches 165 degrees Fahrenheit. Remove chicken from the skillet and set aside on a plate to rest.
In the same skillet, add the chopped rhubarb, chicken broth, honey, balsamic vinegar, and soy sauce. Stir and scrape up any browned bits from the bottom of the pan.
Bring the mixture to a simmer and cook for 8-10 minutes, or until the rhubarb breaks down into a thick, savory-sweet sauce. Stir in the butter until melted and smooth.
While the sauce simmers, steam the broccolini in a medium pot with a steaming basket for 4-5 minutes until tender-crisp.
Serve the pan-seared chicken topped with the warm rhubarb sauce, accompanied by the roasted potatoes and steamed broccolini. Garnish with fresh chopped chives.