Place blueberries and red currants into a mixing bowl. Add 2 tablespoons mint, 2 tablespoons cilantro, marjoram, habanero, olive oil, agave syrup, and juice of 1 lime. Mix until combined and set aside.

Heat a nonstick griddle over medium-high heat. Cook cashews until browned, stirring often to keep from burning, 8 to 10 minutes. Transfer cashews to a plate and set aside. Reduce heat to medium and brown halloumi cheese slices until golden brown, 2 to 3 minutes per side.

Arrange halloumi slices on a serving plate, top with berry salsa mixture and remaining 1 tablespoon mint and cilantro. Chop cashews and spread on top of halloumi. Garnish with lime wedges from remaining lime. Serve immediately.