My question involves a roommate in the State of: California

I rent a room in a house with an absentee landlord. (Each of three bedrooms is rented out individually). I have lived here for five years. Three months ago, a new tenant moved in. He brought a great deal of kitchen stuff because he likes to cook. He has access to over half the kitchen cabinets, and has since he moved in.

More than once since he moved in, he has rearranged the kitchen to his liking. Every appliance on the countertops is his. (My small, collapsible dish rack is my only belonging on the counter; we have no dishwasher, and he uses my dish rack for all his drying). When he moved in, he (without asking) removed everything from the small cabinet I use, boxed it all, put it in a closet, and then stocked the cabinet with his stuff.

I had no idea what had happened, only suspicion, since in our only meeting he had raved about what a foodie & a good cook he is. Without proof that he had been the one who had removed my things, I remained mum in the interest of harmony, even though I was freaked out for several days because he did not leave a note afterward (I found out three days later), or tell me of his intent beforehand.

Since then I have been relegated to a tiny section of a cupboard, and the roommate now says he is going to take even more of the space in the cupboards/cabinets because he is getting more of his kitchen stuff shipped to him.

Is it legal for him to move my stuff without my permission, without telling me? Is it legal for him to unilaterally decide who gets how much space?