1. I lay the tomato slices on the top.

2. I lay the tomato slices on top.
(Are both OK?)

My Recipe for Making Vegetable Soup
Ingredients:a radish, a carrot, a head of cabbage, an eggplant, many leeks, many mushrooms

1. Rince cabbage, an eggplant, many leeks, and many mushrooms by running water ovet it in a big container.

2. Drain them in a colander.

3. Rinse a radish, a carrot, and an eggplant as well.

4. Slice them with a knife on a cutting board.

5. Mix them in a pot.

6. Lay the pot on a gas stove.

7. Add hot pepper paste powder and sesames into the pot.

8. Boil them for some time, and then simmer them for 30 minutes.

9. You can enjoy the vegetable soup.
(Are the sentences all grammatical? If you find any wrong expressions, correct them, please.)

1 and 2 are both OK; 2 is more common.

In the recipe:

1 - Delete the words "many" and correct the spelling of "over."

2 - OK

3 - Replace the first "a" with "the" and delete the other two ("a" and "an").

4 and 5 - OK

6 - Replace "Lay" with "Put" (I don't know why!).

7 - Replace "sesames" with "sesame seeds" or "sesame oil" -- whichever you mean.

8 - Replace "them" with "it" since you are now referring to ONE thing -- soup!

9 - OK

Nice job!