Story of Seasons: Friends of Mineral Town is different from the original game in a couple of ways. Some of the NPCs have additional functions, and some of the ways you will get certain items in the game have changed. One of the things that have changed is how you get a kitchen.
To get a kitchen in Story of Seasons: Friends of Mineral Town, you will need to visit Gotts Workshop, show on the map below. Gott is a very useful character, and he can expand upon your house and farm, as long as you have the lumber and stone to get the job done, and the gold to pay him for his services.
You will need 150 Lumber, and 50 Stone to purchase the Slightly Bigger House upgrade, and this upgrade comes with a kitchen. You will also need 3000 Gold, and it will take Gott three days to finish the project. You actually won’t really need the kitchen for quite a while, as it will take a lot of work to get everything you need to actually cook.
It is important to get it as soon as possible, as the General Store will start to occasionally sell items that you need for the kitchen, like an oven and rolling pin, and the sooner you can get them all, the better. You will also need to expand your farm to make some of the ingredients that you need, which will take a lot of work and resources to do.