Step 1Heat the oven to 350 degrees. Butter a 13-by-9-inch baking dish and set aside.
Step 2Cut the crusts off the bread and discard the crust. Tear the bread into 1-inch pieces; it's OK if they're slightly uneven in size. Toss the bread in one-fourth cup of the olive oil. Place the bread on a baking sheet and bake until crispy on the outside but still tender on the inside, about 15 minutes. Let the croutons cool, then place them in a large mixing bowl.
Step 3Reduce the oven temperature to 325 degrees.
Step 4Meanwhile, heat one-fourth cup of the oil in a 12-inch, wide-bottomed skillet over medium-high heat. Add the rosemary and chiles and let them sizzle in the oil to release their flavors, 30 seconds. Add the onions, diced fennel, garlic, fennel seeds, lemon zest, thyme and half a teaspoon of salt. Cook, scraping the bottom of the pan with a wooden spoon often as the vegetables brown, about 15 minutes. When they are browned, turn off the heat and stir in the sage and the currants. Add to the bowl with the croutons. Toss well.
Step 5Return the skillet to the stove, add 2 tablespoons of oil, and cook the chard over medium-high heat until wilted, 6 to 7 minutes. Add to the mixing bowl.
Step 6Heat a small skillet over medium high-heat and add the butter. Season the chicken livers with salt and pepper and cook until medium-rare, 4 to 5 minutes. They should be a little browned on the outside and a little pink on the inside. Chop and add to the bowl. Toss well. Season the stuffing with the remaining 2 tablespoons of oil and the balsamic vinegar. Mix the stuffing with your hands, gently mashing the ingredients together so they are well blended.
Step 7Place the stuffing in the baking dish, cover with foil and bake 20 minutes. Uncover and bake until the top is golden and crisp, another 20 minutes.