Cover 1 cup raw cashews with boiling water. Let soak until the water has cooled to room temperature. Drain the cashews well after soaking. This is important to make a thick mayo.
Make lemongrass mayo
Trim the top and bottom of the 3-4 stalks lemongrass to leave 4-inch sections. Slice in half lengthwise. Smash the bulb end and peel away and discard the tough green outer layers. Cut away any remaining bulb root. Mince the tender pale insides that are left to a fine texture. Measure out ¼ cup of prepared lemongrass.
Place minced lemongrass in a high-powered powered blender with drained cashews, 3 TB lemon juice, 1 tsp. Dijon mustard, 1 tsp. Braggs liquid aminos, 3 TB avocado or plain oil, and ¼ cup cold water.
Blend lemongrass mayo on high until very, very smooth. Stop the blender a few times to stir the mixture down from the sides of the jar. At first, the mayo will be grainy. Keep blending though, and eventually, it will become silky and fluffy. This may take several minutes. Place lemongrass mayo in the refrigerator while preparing quick pickle.
Make quick pickle
Place ⅓ cup very hot water, ⅔ cup rice vinegar, ¼ cup agave syrup or natural sweetener of choice, and ½ tsp. salt in a 2 cup jar or bowl that has a lid. Stir well to dissolve the salt.
Slice carrots and jicama or daikon into julienne strips. Add 1 cup carrots and 1 cup jicama or daikon to the marinade and cover the container. Let sit for 10 minutes at room temperature. Give a shake and place in the refrigerator to chill.
Assemble Banh mi sandwiches
Cut 4 six-inch Banh mi rolls in half lengthwise. Have ready 1 ¼ cups vegan pate, 1 cup cucumber , thinly sliced, ½ cup cilantro leaves, ½ cup mint leaves, and 2 small jalapeno peppers, sliced in rings. Take lemongrass mayo and quick pickle from the refrigerator.
Spread one side of each roll with a generous amount of lemongrass mayo. Spread the other side with about ⅓ cup of pate. Top with ½ cup carrot and jicama pickle and ¼ of the cucumber slices. Garnish generously with fresh mint and cilantro. Add jalapeno slices if desired. Fold the two sandwich halves together.
Serve
Serve with extra rings of sliced jalapeno and Bragg's liquid aminos or soy sauce for each person to add to taste.
Store
Extra lemongrass mayo keeps in a covered container in the refrigerator for 7 days.
Notes
Recipe tips Smash - the bulb end of lemon grass and remove all the tough green layers until you have the tender insides left to mince. I use my espresso coffee tamper! That's because it's always handy and fits well in my hand. But you can use any sturdy kitchen mallet or heavy, flat-bottom device.Make lemongrass mayo first so it can chill while preparing other ingredients. If you have the time, it's even better made a day ahead.Blend - the lemongrass mayo until it's perfectly smooth and fluffy.Quick pickle - is exactly that. Let it sit for 10 minutes, and use it after a brief chill.Vegan pate - several types can work. Select one made with mushrooms or other umami-rich flavors and a smooth, thick texture. This consistency is complimented by the crunchy veggies and soft bread.Pile fresh mint and cilantro generously on your vegan Banh mi sandwich.Sprinkle Bragg's liquid aminos or soy sauce lightly over the fresh herbs for that final touch of Asian flavor. A little goes a long way!