1. Preheat the oven to 375°F.
2. Cook the beets in large pot of simmering water for about 45 minutes or roast whole in the oven until tender when pierced with a knife. Slip off the skins and slice the beets into thin ¼” slices.
3. For the lemon feta, in a food processor fitted with a metal blade place the feta, garlic, lemon juice, zest and olive oil and process until smooth and combined, about 30 seconds. Scrape down the sides of the bowl with a spatula and process for 1 minute more until light and airy. Stir in the chives. Scrape the feta into a bowl.
4. Place two sheets of fillo on a parchment paper lined baking sheet. Brush all over with some of the melted butter. Add two more sheets of fillo and brush with more butter. Finally layer the last two sheets on top and fold in the edges to make a little ½” border all the way around creating a 10” x 13” tart base. Brush with more butter.
5. Using a spatula spread the lemon feta evenly over the fillo all the way to the borders. Layer the beets randomly over the surface of the tart. Brush beets lightly with remaining butter. Season lightly with salt and pepper.
6. Bake for 27 to 30 minutes until fillo is golden and crisp.
Let tart cool for ten minutes and then garnish with fresh basil leaves or micro greens and some thinly shaved candy cane beets if desired.
Cut tart into squares and serve warm with your favourite salad.