1Place the beets in a large pot, cover with cold water, and bring to a boil over high heat. Once boiling, reduce the heat to medium and simmer until the beets are fork tender, about 30 minutes. Drain, then peel under cold running water. Set the beets aside to cool.
2Trim any green tops off the fennel and slice the bulbs in half lengthwise. Remove the core from each half and slice the bulbs lengthwise in 1/4-inch-thick strips.
3Return the large pot to the stove, add the olive oil and butter, and heat over medium heat. When the butter foams, add the fennel, season well with salt and pepper, and cook, stirring occasionally, until just tender, about 5 minutes.
4Add the vermouth, mustard, and lemon juice and bring to a simmer. Meanwhile, slice the peeled beets into 1/4-inch-thick rounds. Add the beets to the pot and cook until warmed through, about 5 minutes more. Stir in the herbs, taste, and adjust the seasoning as desired.
Beverage pairing:Château de La Chaize Brouilly, France. Beets can be great with either white or red wine, but the Gamay grape from Beaujolais is particularly adept at matching a beet’s combination of earthy and sweet flavors stride for stride. The wine is dry, but is a lovely combination of soil, grape, and leaf tastes, matched with some punchy tannins and acid to give the whole combination some structure.