Preheat oven to 400°F. Wrap each beet individually in foil and roast for 45 minutes or until tender when pierced with a fork.
Allow beets to cool, then peel and cut into cubes.
In a small bowl, whisk together Dijon mustard, lemon juice, olive oil, honey, salt, and black pepper until emulsified.
In a large serving bowl, gently toss the roasted beets, diced avocado, sliced basil, and feta chunks with the dressing.
Add baby salad leaves and toss lightly to combine.
Top with toasted pumpkin seeds and serve immediately.