I have salad with meat or fish or boiled eggs for lunch 5 days per week. I dress it with balsamic vinegar, olive oil and seeds. Before I went to 2 meals per day, my breakfast was always eggs (boiled, poached, fried, scrambled or an omelette).
I have never used a low carb/keto recipe, I just avoid those foods that me BG meter tells me spike my Blood Glucose too much. So I stick to simple food chosen from meats, fish, eggs, cheese, full fat greek style yogurt, nuts, berries, avocados and low carb veg like broccoli and cauliflower.