Rinse winter melon slices; drain in colander. Sprinkle liberally with salt and set aside. Rinse dried shrimp briefly under running water. Soak in enough warm water to cover at least 30 minutes. Drain and set aside. In a wok or large pot, heat oil over medium high heat until just smoking. Add bacon; fry until just beginning to render fat. Add onion, garlic and shrimp. Add sugar, season with salt and pepper and stir-fry until onion just begins to turn translucent, about one minute. Add winter melon; toss to coat. Stir-fry about 30 seconds. Add chicken stock; bring to a boil. Reduce heat, cover, and simmer until melon is just fork-tender, about ten minutes. Check seasonings, add sesame oil and serve at once.