Drain the 400 g firm tofu and tear it into bite-size chunks.

Mix 4 tbsp unsweetened vegan yogurt, 1 tbsp lemon juice, 2 tsp agave syrup, 1 tsp smoked paprika, 1 tsp ground cumin, 1 tsp dried oregano, 1/2 tsp dried thyme, and salt in a mixing bowl.

Add the tofu chunks to the marinade and stir until evenly coated.

Set the marinated tofu aside while preparing the tzatziki.

Grate 1/2 cucumber and squeeze out as much liquid as possible through a fine-mesh sieve.

Combine the grated cucumber, 200 g unsweetened vegan yogurt, minced garlic, chopped mint, chopped parsley, 1 tbsp lemon juice, salt, black pepper, and olive oil in a clean bowl.

Stir the tzatziki until creamy, then set it aside for serving.

Thread the marinated tofu pieces evenly onto 6 wooden skewers.

Heat a grill pan over medium-high heat and arrange the tofu skewers in the hot pan.

Grill the tofu for 5 to 10 minutes per side, turning with tongs until golden brown.

Slice the remaining cucumber, tomatoes, and red onion into thin serving pieces.

Fill each pita bread with grilled tofu, tzatziki, sliced cucumber, tomato, and red onion.

Serve the tofu souvlaki pitas immediately while the tofu is hot.