All meats, poultry, fish, eggs. All can be precooked, packaged and frozen for other meals. If you eat dairy, cheese and cream, not milk. All ABOVE ground veggies, not starchy such as potato, rutabaga, sweet potato. Think green veggies. Bell peppers, carrots, peas and onion are higher carb. I'm not sure how low carb you want to go. Healthy fats like olive oil, avocado, olives, nuts and seeds. Cashews and peanuts are higher carb
If short on time buy bagged lettuce and throw some protein, olive oil or full fat dressing, avocado chunks and a few nuts if you wish and good to go for lunch or dinner. Many just eat deli meat and cheese with a few tomatoes. Hard boiled eggs on the run. Make crustless quiche or eggs with sausage and a few veggies baked in muffin tins. Heat and eat. So many options. Sometimes taking some time on the weekend to cook and freeze many meals works well for the week. I have loads of a variety of precooked protein. Salmon turkey chicken shrimp rare beef and lamb, can see of tuna and salmon. Infreeze in my portion size baggies and defrost in water for 15 min. My hubby leaves it in his desk and ready and defrosted by lunch. Then we grab some veggies and some fat. Frozen veggies are chopped and cut asp d take minutes to steam.
In the beginning it takes a little planning and cooking but soon becomes routine.
https://www.dietdoctor.com/low-carb That should get you started
I tend to like to keep things simple and spend as little time in the kitchen as I can. No menus or recipes needed. Protein, veg, fat. Done. If proteins are precooked and ready to go I just steam some veg or grab some lettuce. Add avocado and olive oil. 5 minute meal. I'd rather cook 10 chicken breast / thighs at one time than cook them at each meal. Less dishes, less time, less planning, less thinking, less shopping. Not sure where you're located but if in the U.K. I hear there are loads of ready meals. I think
@Brunneria does the same as me for the most part. I do think she cooks more though haha
Hope that helps.