Bake the falafel according to the package directions, usually at 400°F for 12–15 minutes.

Whisk tahini, lemon juice, water, and salt in a small bowl until smooth.

Warm the buns in the oven for 2 minutes.

Slice each bun and spread the tahini sauce on both sides.

Add lettuce, falafel, tomato, and parsley. Close the sliders and serve warm.