In a small mixing bowl, combine the avocado with 3/4 of the lemon juice and 1/4 teaspoon of salt.: The scent here should be bright, a hint of citrus rising from the mashed avocado , and the texture should be creamy with a few small lumps remaining. I pay attention to the salt level early, because it wakes up the avocado without overpowering it. If the mixture smells overly fatty or flat, add the remaining lemon juice a little at a time until a lively acidity comes through. One common mistake is over mashing, which removes pleasant little chunks that add texture, so stop when it is mostly smooth but still a bit rustic.
On a work surface, spread a large spoonful of hummus over half of a tortilla. Spread a spoonful of the avocado mixture over the other half. Place a handful of carrot sticks in the center, top with a sprinkle of radishes, and 1/4 cup of arugula leaves. Fold in the top and bottom sides of the tortilla. Fold in one of the sides length-wise and roll the tortilla, making sure the top and bottom stay tucked. Repeat with the remaining tortillas.: The hummus should be spread in an even, thin layer so there is flavor in every bite without making the tortilla soggy. As you spread, notice the aroma of the hummus, especially if it is chipotle, which will add a smoky perfume. If the hummus piles up in clumps, it can tear the tortilla when you roll, so smooth it out evenly. Avoid using too much hummus directly against the tortilla edge, which can force filling out when you roll.
Spread a spoonful of the avocado mixture over the other half: The contrast of textures becomes apparent here, creamy avocado on one half and dense hummus on the other. Visually, you want two distinct panes of flavor that will meet in the middle when the wrap is folded. If the avocado looks pale, a touch more lemon will brighten it. A common slip is over stacking spreads which can make the roll bulky and hard to close.
Place a handful of carrot sticks in the center: When you add the carrot sticks, pay attention to the crunch sound as you drop them in, it is a nice confirmation of freshness. Arrange them lengthwise, keeping them mostly in the center so the roll can fold cleanly. If the carrots feel soft or bendy, they may be old, and will not contribute the crisp bite we want. Avoid piling them too high which can break the tortilla when rolling.
Top with a sprinkle of radishes: The thinly sliced radishes should sit atop the carrot sticks; their peppery aroma will mingle with the lemon kissed avocado . Look for a bright white interior with a rosy edge, a sign of freshness. If the radishes are watery, they can add unwanted moisture, so pat them dry. A frequent mistake is using thick radish slices which can dominate the mouthfeel instead of adding a delicate crunch.
Add 1/4 cup of arugula leaves: The tender peppery arugula adds leafy lift and a slightly bitter counterpoint. Lay the leaves gently so they do not crush the radishes or carrots, and check that they are dry to prevent sogginess. If the leaves are wilted, they will not provide the intended freshness, so swap them out. Too many leaves can make the roll bulky and cause it to spring open after rolling.
Fold in the top and bottom sides of the tortilla: You want a compact envelope before you roll, so fold the top and bottom edges inward about an inch. As you fold, listen for a slight rustle, which indicates the tortilla is moving into position. This step creates barriers that keep the fillings from escaping. A common error is skipping this tuck, which leads to loose ends and filling leakage during rolling.
Fold in one of the sides length wise and roll the tortilla, making sure the top and bottom stay tucked: Start by folding one side over to meet the other, then roll gently but firmly, using the tucked edges as guides so nothing spills out. The finish should feel snug, the tortilla slightly warm to the touch if you softened it earlier, and you should see neat layers along the seam. If the roll feels loose, press lightly and re tuck before continuing. Rolling too tightly can cause the tortilla to split, while too loosely will let fillings fall out.
Repeat with the remaining tortillas: As you assemble the rest, keep an eye on consistency so each wrap has similar balance. I taste a small corner of a finished wrap to ensure seasoning is right, the lemon and salt on the avocado should complement the hummus . One pitfall is inconsistent spread amounts, which leads to some wraps being bland and others overwhelming, so measure roughly by eye for evenness.