Boil a pot of water and add kosher salt. Soak wooden skewers in water for 30 minutes. Boil summer peppers (1 to 2 per skewer) until tender, 1 to 33 minutes. Drain. Thread onto skewers with cherry tomatoes (about 3 per skewer). Grill over high heat until charred and tomatoes just begin to burst, 6 to 8 minutes, turning often.