Cut out carbs as many as you are able.
You can eat loads of things - above ground veg, meat , fish ,seafood, eggs ,cream, butter and yes steak tartar if you like. Full fat everything.
You can eat most normal food that isn't
a: high in carbs i.e. starch and sugar
b: junk food high in carbs and/or additives/chemicals
Learn to read and interpret the nutritional labelling on packaging for information - it's a reasonable guide; or try supermarket (I found Tesco's a godsend when I first started on a low carb diet) or manufacturers websites, and ask Google - or on here - where you're in doubt.
It is the carbs that you need to watch and be aware of. I tend to think of food in it's natural / fresh form so fish (but not battered from the chippy ), pork, chicken, beef but lean cuts if you can, veggies but limit and restrict those that grow below ground i.e. potatoes, swede. Eggs are good - even better with bacon but just watch if you put them in a butty as bread is really carby - look for a wholemeal or a stone ground loaf and the more grains/seeds in the bread the better. It's a bit of an education when you start reading the food labels and checkng carbs per slice etc
And as for alcohol to accompany your steak . . . Red wine is a good choice . My hubby who is also diabetic (T2) finds he can drink vodka and diet tonic without it impacting on his blood sugars but just remember that we are all different.