Ingredients:

1. 500 grams of fresh mushrooms, cleaned and sliced

2. 1 cup white vinegar

3. 1/2 cup olive oil

4. 1/4 cup sugar

5. 2 tablespoons salt

6. 1 tablespoon mustard seeds

7. 1 teaspoon turmeric powder

8. 1 teaspoon red chili powder (adjust to taste)

9. 4-5 garlic cloves, finely chopped

10. 2 tablespoons ginger, finely grated

11. A few curry leaves

12. 1/2 teaspoon asafoetida (hing)

13. 2-3 green chilies, slit (optional)

Instructions:

1. Start by heating a large pan. Add the olive oil and mustard seeds. Wait for the mustard seeds to splutter.

2. Add the chopped garlic, grated ginger, curry leaves, and green chilies. Sauté for a minute or so until the garlic turns golden.

3. Now, add the turmeric powder, chili powder, and asafoetida. Stir well to mix the spices with the oil.

4. Quickly add the sliced mushrooms to the pan. Mix well to ensure the mushrooms are coated with the spices.

5. Cook the mushrooms on medium heat for about 5-7 minutes. They will release water. Let this simmer until most of the water evaporates.

6. Once the mushrooms have softened and the water has mostly evaporated, add the vinegar, sugar, and salt. Mix everything well.

7. Continue to cook for another 5 minutes. The mixture should look glossy and the oil will start separating.

8. Taste and adjust the salt and sugar if needed. Remember, pickles usually have a stronger taste as they are consumed in small quantities.

9. Turn off the heat and let the pickle cool completely.

10. Once cooled, transfer the mushroom pickle to a clean, dry, sterilized jar. Ensure the pickle is covered with oil at the top to prevent spoilage.

11. Store the jar in a cool, dry place. The pickle will develop its flavors over a few days.

This mushroom pickle pairs wonderfully with rice, bread, or as a side dish to add a tangy, spicy kick to your meals. Enjoy your homemade delicacy!

Further Storage etc for commercial scale:

For preserving, cooling down the pickle after cooking is essential to avoid condensation inside the jar. It's important to ensure the pickle has enough acidity from vinegar or lemon juice, which is crucial for preventing bacterial growth. Before sealing, make sure there's a layer of oil on top of the pickle to act as a barrier against air and microbes.

In packaging, start by sterilizing glass jars and lids by boiling them in water for 10 minutes.

Dry them completely before use. Fill the jars with the pickle, making sure there are no air pockets, and leave a small space at the top. Seal the jars tightly to prevent any contamination.

For canning, place the filled jars in a canning pot with water covering the jars by at least an inch. Bring the water to a boil and process for about 10 minutes, although this time might vary depending on your altitude. After boiling, remove the jars and let them cool for 12-24 hours.

Check the seal to ensure it's airtight.

Sunning is an optional method where you place the filled jars in direct sunlight for 2-3 days. This is a traditional method believed to enhance the pickle's flavor and longevity. It's important to check the jars daily to ensure no moisture is forming inside, especially in humid conditions.

For storage, keep the jars in a cool, dark place like a pantry or cupboard, away from direct sunlight and fluctuating temperatures. After opening, it’s best to refrigerate the pickle.

Properly canned and sealed pickles can last up to a year or more unopened.

Once opened, it's best to consume them within a month or two for the best taste and quality. Always use clean utensils when handling the pickle to prolong its shelf life. Remember, maintaining cleanliness and ensuring no contamination are key in preserving pickles.