Yogurt format. 1.75 kg ≈ 1.65 L by volume. Two 750 mL tubs gets you to 1.5 L; if your store carries a 1 kg or larger tub, that's the cleanest single buy.
Frozen vs fresh kale and broccoli. Nutritionally near-identical, dramatically faster prep. Costco and most grocers carry 1 kg+ bags of both. Stock both.
Chicken batch-poach. Two large breasts simmered 18–20 min in salted water, shredded with two forks while warm, refrigerated in pulled form. Lasts 4 days; cook a second batch Wednesday.
Tuna substitution. If you'd rather use chicken on all 3 low days, drop tuna entirely and bump chicken raw weight to 2.0 kg. Tuna is here for variance and shelf-stable backup.
Sunday batch prep, ~30 min. Cook 4 cups dry barley → ~12 cups cooked. Roast 1 kg yellow potatoes, cool, refrigerate (resistant starch). Brown 1 kg ground beef with garlic and onion, portion into 4 servings. Hard-boil 6 eggs as backup protein.