Take 300 gm of guava (2 pieces) and cut them into thin slices. Remove the central part to deseed them. (Pro tip: Do not take those fully ripe and yellow guavas as these might have some worms in them. Take ones that are a little green in color).
Cut them into smaller pieces.
Transfer the pieces of guavas to a mixer grinder.
Now, add 1 cup of fresh coriander leaves without their stem, 3 to 4 pieces of fresh green chilies (cut roughly), and 1 piece of ginger of about 1 inch in size (deskinned and diced roughly) into the grinder. (Pro tip: You may increase or decrease the number of green chilies according to your preference or the amount of chutney you want to make).
Then, add 2 tbsp of fresh lemon juice. One standard-size lemon will be enough to squeeze this much juice.
Now, add ½ tsp of coriander powder, ½ tsp of cumin powder, and ¼ tsp of pepper powder to the content in the grinder, asafetida powder, ½ tsp each of black salt and regular table salt, and finally a little bit of water into the grinder.
Now, grind the ingredients to get a fine paste. Check the consistency and if you think it is too thick, add some more water and blend it again. (Pro tip: Do not add a lot of water initially while grinding. Since you will not be able to take back what you have added, check the consistency, add water gradually if needed, and blend it every time after adding water till you get the desired consistency of the paste. Blend it in short intervals so that the heat generated by the rotating motor of the grinder does not change the color of the chutney).
When you are happy with the consistency, transfer the paste to a bowl and your tasty, homemade guava chutney is ready to be served alongside a variety of dishes and snack items.