You should base the majority of your meals around these foods:
Meat: Red meat, steak, ham, sausage, bacon, chicken and turkey.
Fatty fish: Such as salmon, trout, tuna and mackerel.
Eggs: Look for pastured or omega-3 whole eggs.
Butter and cream: Look for grass-fed when possible.
Unprocessed Cheese: cheddar, goat, cream, blue, mozzarella.
Nuts and seeds: Almonds, sunflower, walnuts, flax seeds, pumpkin seeds, chia seeds, etc.
Healthy oils: Primarily extra virgin olive oil, coconut oil and avocado oil.
Avocados: Whole avocados or freshly made guacamole.
Low-carb veggies: Most green veggies, tomatoes, onions, peppers, etc.
Condiments: You can use salt, pepper and various healthy herbs and spices.
It is best to base your diet mostly on single-ingredient whole foods.