In a small bowl, toss the shrimp with the five-spice powder and cornstarch. In another small bowl, mix the oyster sauce, rice wine vinegar and 2 tbsp. water.
In a large skillet, heat the sesame chili oil over medium-high. Add the onion, pepper, ginger and 1 tbsp. water, and stir-fry until vegetables soften, 2 to 3 minutes. Add the shrimp and cook 2 minutes. Add the snow peas and sauce. Cook until the shrimp are opaque in the center and the sauce thickens, 2 to 3 minutes. Garnish with the peanuts.