Prepare and roast the beets: Preheat your oven to 400°F (200°C). Wash the beets thoroughly and trim off the tops and roots. Wrap each beet individually in aluminum foil and place on a baking sheet. Roast for 45-60 minutes until tender when pierced with a fork. The time will vary depending on the size of your beets.
Cool and peel the beets: Allow the roasted beets to cool enough to handle, then use paper towels to rub off the skins (they should slip off easily when roasted properly). Cut the beets into small ½-inch cubes and place in a bowl.
Season the beets: Toss the cubed beets with 1 tablespoon olive oil, minced garlic, a pinch of salt, and freshly ground pepper. Set aside to marinate while preparing the crostini.
Make the crostini: Preheat oven to 375°F (190°C). Arrange the baguette slices on a baking sheet, brush both sides lightly with olive oil. Bake for 7-10 minutes until golden and crisp. While still warm, rub one side of each toast with the whole garlic clove.
Prepare the goat cheese spread: In a small bowl, mix the goat cheese with 1 tablespoon olive oil, half the lemon zest, and a pinch of salt until smooth and easily spreadable. For a fluffier texture, you can whip it with a mixer or food processor.
Assemble the crostini: Spread a generous layer of the goat cheese mixture on each crostini. Top with a spoonful of the seasoned beet cubes.
Add the finishing touches: Drizzle each crostini with a small amount of honey and balsamic glaze. Sprinkle with the remaining lemon zest, fresh herbs, and toasted nuts if using.
Garnish and serve: Add a few microgreens or arugula leaves on top if desired. Arrange on a serving platter and serve immediately while the crostini are still crisp.