Place the almonds in a bowl with 1 cup water; let stand for 3 hours. Drain, reserving the liquid.
Using a blender, chop the almonds and garlic with 1/4 cup soaking liquid, 1 1/2 tbsp. lemon juice and the mustard. With the machine on, slowly pour in the EVOO. Blend for 5 minutes; season. Transfer the almond mayo to a bowl.
Place the onion in a bowl. Add the remaining 1 tbsp. lemon juice; toss.
Fill a large rimmed plate with water. Dip both sides of 1 wrapper in the water. Place on a work surface; spread with 1/2 tbsp. almond mayo. Dip another wrapper in the water; place on top. Spread with 1 tbsp. almond mayo.
Place a handful of spinach in the center of the stacked wrappers. Top with some onion, mushrooms, pepper, broccoli and grapefruit; roll up. Repeat with the remaining wrappers, almond mayo and toppings. Before serving, cut each wrap in half.