Heat the oven to 400°F (205°C). Rub the beets lightly with olive oil, wrap loosely in foil, and roast on a tray for 45–55 minutes, until a knife slides in with no resistance. Time depends on size — start checking at 45 minutes.
While the beets roast, toast the pistachios in a dry pan over medium heat for 3–4 minutes, stirring often, until fragrant and lightly colored. Move them off the heat right away so they don't scorch. Roughly chop once cool.
When the beets are cool enough to handle, rub off the skins with a paper towel — they slip away easily. Slice into rounds or wedges.
Whisk the olive oil, red wine vinegar, honey if using, and a pinch of salt and pepper into a simple dressing.
Arrange the beets on a platter (over soft greens, if using). Crumble the goat cheese over the top, scatter the pistachios, and spoon the dressing across. Finish with flaky salt, a few thyme leaves, and a last thread of olive oil.
Serve at room temperature, with the wine poured slightly cool. Let it sit a few minutes before serving so the flavors settle.