1) Toss together first 6 ingredients and 1 tablespoon wine. Let stand 30 minutes or more if you want to do this step ahead of time. Meanwhile, stir together hot water, hoisin, and remaining tablespoon of wine.
2) Remove beef from marinade. Add salt and black pepper. Cook beef in 1 tablespoon hot oil in a large skillet or wok over high heat, without stirring, 45 seconds or until browned; turn beef, and cook about 30 seconds or until browned. Transfer to a plate and cover with foil to keep warm.
3) Stir-fry onion in remaining tablespoon of hot oil in wok or large skillet over medium-high heat 2 minutes. Add sugar snap pea or green beans, ginger, and red pepper. Stir-fry for 2 minutes or until pea or beans (beans will take longer depending on their thickness) are tender but still crisp. Add beef and hoisin mixture. Stir-fry 1 minute or until slightly thickened. Remove from heat. Stir in watermelon. Add salt, black pepper, and red pepper to taste. Serve immediately with hot cooked rice or quinoa. Tastes great the next day for leftovers.