Crumble tofu into a large bowl, forming a mixture of large and small chunks. Add mushrooms, salsa and 2 tablespoons chopped coriander stems and roots; stir well to combine.

Heat 1 tablespoon of the oil in a large, heavy-based non-stick frying pan over high heat. Add half the mushroom mixture; cook, stirring occasionally, for 8 minutes or until mushrooms are browned and tender. Transfer to a bowl. Repeat with remaining oil and mushroom mixture. Return all mushrooms to the pan with corn; stir to combine. Season to taste. Remove pan from heat; cover to keep warm.

Meanwhile, heat a chargrill pan over medium heat; cook tortillas, one at a time, for 30 seconds each side or until char marks appear. Transfer to a plate; keep warm.

Process cottage cheese and avocado until smooth. Season to taste.

Stir ½ cup coriander leaves through mushroom mixture; divide among tortillas. Top with tomatoes and remaining coriander leaves. Serve tacos with the avocado-cottage cheese, drizzled with extra oil, if you like.