Attempted to make kebabs; they had too much moisture.

I had lean beef keema so I decided to make kebabs. I used all typical spices; chilli powder, cumin, coriander, garam masala. you get it. I also added ginger garlic paste and cornstarch. I used one onion but I first strained it to remove all the moisture.

The kebabs were still too moist. I also bought it from a butcher shop so there was some blood. I used a strainer to remove all the liquids. No luck.

Any tips? thanks!