Preheat the oven to 400°F (200°C). Arrange the beet slices on a lined baking sheet and drizzle with 1 tablespoon of olive oil. Roast for 35-40 minutes until the beets are tender and slightly caramelized, with edges beginning to brown.
Remove the roasted beets from the oven and let them cool slightly. While still warm, transfer the beets to a blender or food processor.
Add the peeled garlic cloves, tahini, and 1 tablespoon of olive oil to the blender. Blend until smooth and creamy, scraping down sides as needed. If the mixture is too thick, add a splash of water or extra olive oil to achieve a spreadable consistency.
Transfer the hummus to a serving bowl. Squeeze fresh lemon juice over the top and season with cracked black pepper. Optionally, drizzle with a bit of olive oil and sprinkle additional black pepper for presentation.
Serve the roasted beet hummus with vegetable sticks, pita chips, or as a spread for bread. The vibrant color and creamy texture make it visually appealing and flavorful.