Clean the chanterelles thoroughly with a kitchen towel, cut off the stalks and, if necessary, cut away any damp spots. Cut mushrooms into slices and set aside. Clean the chicken fillet and remove any tendons. Season on both sides with salt and pepper and sauté with a teaspoon of olive oil in a skillet over medium-high heat for 5 to 8 minutes on each side until it's cooked through.
Meanwhile, bring the pasta water to a boil and sauté chanterelle in a second pan without oil over medium-high heat for 4 to 5 minutes. (If too much water accumulates in the pan during this process, simply drain in between. Mushrooms are done when there is no more water in the pan and mushrooms are slightly roasted). At the same time, wash sage leaves, peel garlic cloves and finely slice both.
Remove the chanterelles from the pan. Add the remaining olive oil to pan and sauté garlic and sage with plenty of salt over low heat for 2 to 3 minutes. Meanwhile, cook pasta according to package directions (about 2-3 minutes). When garlic and sage have light toasty aromas, reduce the heat to low, deglaze with white wine, and add finished pasta, give it a good mix, add the mushrooms and season again with salt and pepper to taste. Cut the chicken fillets into thin slices and serve on top of pasta along with the pesto.