Place the mushrooms onto a baking tray. Sprinkle a pinch of salt, a grinding of pepper and a drizzle of olive oil over the top. Place into the oven for 30 minutes.
Take your Meatless Burgers out. Sprinkle some salt and a grinding of pepper over the top. Add 1 tsp of chipotle paste to each burger and rub it over the burgers, making sure you cover the whole burger with the paste.
Pesto time. Into a food processor, add the basil, chives, tarragon, walnuts, garlic cloves, a sprinkle of salt and pepper, a tbsp of olive oil and the juice of a whole lemon. Blend until smooth.
Add a generous drizzle of olive oil into a frying pan and place your Meatless Burgers in. Cook for 5 minutes on either side.
While the burgers are cooking, lightly toast your burger buns so they begin to char, take them out and set aside. Next, slice up your tomatoes and grill them in a lightly oiled pan until they just begin to turn soft, set aside.
Assembly time. Halve your burger buns. Take a tbsp of pesto and dollop it on one half of your burger bun, place your Meatless Burger on top. Next, add a mushroom and 2 slices of tomato. Add another tbsp of pesto to the other half of the burger bun and place it on top. Repeat this for the rest of the burgers, and tuck in!