I'm thinking of not eating food my partner cooked and  making my own meal.
Why would you refuse to eat food that your partner cooked?
I am just tired of eating their food and you know they never like my cooking either?
It's okay to want to eat the food you made over your partners. Not everyone has the same tastes but if you have another personal reason to refuse their food, then you should tell them the reason why. If not they're going to take it as a personal insult and be upset with you.
I just don't feel like eating it. Instead I will be cooking my own food.
That's fine. Maybe you can do a meal plan with them so you don't always both have to be cooking. It might be a good compromise.