What can I use instead of cornstarch to make the custard filling?

Milk yellow filling, sounds delicious. But the online custard filling are to be clarified flour, butter, custard powder, etc., the home-cooked ingredients will not be very complete, remove these, only with the usual eggs, milk, sugar, vegetable oil made of how it will be? I tested it and it was great. Soft, sweet and fragrant sand, egg and milk flavor. It was very much like the lotus seed paste filling in mooncakes. Wow, is this how the lotus seed paste filling in mooncakes is made? I'm not sure if this is a good idea, but I'm sure it's a good idea.

Materials:

Eggs (about 60 grams) 2, sugar 100 grams, 70 grams of milk, 50 grams of soybean oil, 50 grams of corn starch.

Steps:

1, two eggs beaten into a bowl with 100 grams of sugar.

2, beat well.

3, add 50 grams of soybean oil, 70 grams of milk.

4, beat well.

5. Sift in the cornstarch.

6: Beat until there is no dry flour.

7: Place in a boiling steamer and stir every 3-5 minutes or so to prevent large lumps.

8: Steam it after 20 minutes.

Step by step diagram:

1, two eggs into the basin, add 100 grams of sugar.

2, beat well.

3, add 50 grams of soybean oil, 70 grams of milk.

4, beat well.

5. Sift in the cornstarch.

6: Beat until there is no dry flour.

7: Place in a boiling steamer and stir every 3-5 minutes or so to prevent large lumps.

8, 20 minutes after the steam is ready.