Tangy-sweet Harvard beets in a glossy sauce are a classic, vegetarian, healthy family side dish. This vibrant, jewel-toned accompaniment adds color and nutrition to any dinner plate.
Scrub and trim the beets. Place them in a pot with water, bring to a boil over medium-high heat, cover, and simmer for 30–35 minutes until fork-tender.
Drain and let the beets cool slightly, then peel and cut into 1/2-inch cubes. Set aside.
In a saucepan, combine sugar, apple cider vinegar, salt, and 3/4 cup water. Stir and bring to a low simmer over medium heat.
Mix cornstarch with the remaining 1/4 cup water in a small bowl; whisk into the simmering sauce, stirring constantly until glossy and thickened (about 2 minutes).
Add the cubed beets and butter to the saucepan. Gently stir to coat, warm over low heat for 2–3 minutes, then serve immediately for best texture and flavor.