Roast the beets: Place whole beets in an oven-proof dish. Cover with a lid or aluminum foil. Roast in a 400 degree Fahrenheit oven for 25–30 minutes until beets are tender. Remove from the oven and allow to cool until you can handle them with your hands. Slip off the skins with your fingers. If necessary, cut off the root and stem ends. Slice into half-inch wedges and set aside until needed.
Heat a large skillet on medium heat. Add butter and red onions. Cook, stirring occasionally, until the onions start to soften and brown. Add sliced roasted beets, salt, and black pepper, and stir well. Arrange the beets in a single layer on the bottom of the skillet so that each beet is in contact with the cooking surface. Cook undisturbed for 4–5 minutes until the beets start to caramelize. Add the maple syrup and mix gently.
Transfer to a serving bowl. Garnish with minced parsley if you like.
I used golden beets for this recipe. Golden beets have a milder taste, and less of the earthy flavor of red beets. However, if red beets are all you can find, you can definitely use them for this recipe.There are also chiogga beets out there, which have pink and white stripes throughout. These can also be used.