Heat a medium non-stick frying pan over medium heat; cook cumin, sunflower and chia seeds, stirring, for 2 minutes or until seeds are toasted, transfer to a small bowl. add half the rice bran oil, half the lemon juice, onion, parsley and mint; toss to combine; set aside.
Prepare yogurt tahini dressing: Combine all ingredients is a small bowl; mix well. Set aside.
Heat HARVEST GOURMET Vegan Burger according to directions on pack.
Meanwhile, heat remaining rice bran oil in same cleaned non-stick frying pan over high heat; cook mushrooms, thyme and garlic, stirring occasionally, for 4-5 minutes or until browned lightly. Remove from heat, stir through remaining juice.
To serve, divide watercress among serving plates; top with HARVEST GOURMET Vegan Burger patties, a good dollop of dressing; then divide mushroom mixture between patties; top with salad. Serve any remaining yogurt Tahini dressing in a small bowl on the side.