Creating Spicy Shrimp and Mushroom Stir-Fry is straightforward if you adhere to the following steps:

1. Prepare Ingredients: Chop all vegetables and measure out sauces in advance to streamline the cooking process.
2. Heat Wok or Pan: In a large wok or skillet, heat vegetable oil over medium-high heat until shimmering.
3. Sauté Garlic and Ginger: Add minced garlic and grated ginger to the hot pan. Sauté until fragrant, about 30 seconds.
4. Cook Shrimp: Add the shrimp to the pan. Stir-fry until they turn pink and opaque, approximately 3-4 minutes.
5. Add Mushrooms: Next, add the sliced mushrooms and continue to stir-fry for another 2-3 minutes until they soften.
6. Incorporate Vegetables: If using bell peppers, add them at this stage and cook for an additional 2 minutes.
7. Combine Sauces: Pour in the soy sauce, oyster sauce, chili paste, sugar, and black pepper. Stir everything to combine thoroughly.
8. Toss in Green Onions: Just before finishing, add the chopped green onions, mixing well, and allow them to warm for a minute.
9. Serve Immediately: Remove from heat and serve hot over a bed of cooked rice.

By following these straightforward steps, you will create a dish that is not only delicious but also a feast for the eyes.