Prep the veggies: Wash and dry all vegetables. Thinly slice the red bell pepper into 1/4 inch strips. Peel and julienne the carrots. Slice the cucumber lengthwise into thin strips, removing seeds if preferred. Toss spinach with lemon juice, salt, and pepper. If using avocado, slice thin and toss with lemon juice to prevent browning.

Lay out the tortilla and spread hummus: Place one tortilla flat on a clean surface. Spread about 1/4 cup of hummus evenly over the entire surface, leaving a 1/2-inch border around the edges.

Layer the veggies: Arrange a line of spinach, bell peppers, carrots, cucumber, and avocado (if using) about 1 inch from one edge of the tortilla, keeping layers tight and even.

Roll tightly and wrap: Starting from the veggie edge, roll the tortilla tightly but gently. Wrap the roll in plastic wrap or parchment paper and chill for 10 minutes if possible to help hold shape.

Slice and serve: Using a sharp serrated knife, slice each roll into 1-inch pinwheels. Arrange on a plate with the colorful veggie sides facing up.