Pour milk into the blender, then add cottage cheese. Follow the manufacturer's loading order for an inverted personal blender.
Blend 30 to 45 seconds, scraping if needed, until glossy with no visible curds on the jar.
Add frozen banana, mixed berries, honey, vanilla, lemon juice and optional cinnamon and chia.
Blend on low 10 seconds, then high 45 to 60 seconds. Stop before scraping and add milk 1 tablespoon at a time if circulation stalls.
The smoothie should pour in a thick ribbon and feel curd-free. Add frozen fruit to thicken or milk by the tablespoon to thin.
If salty, add more banana or 1 teaspoon sweetener. If flat, add a few drops of lemon; if tart, add sweetener.
Blend on high another 15 seconds after any adjustment.
Divide between two chilled glasses and serve immediately; stir and loosen with milk if it stands more than 10 minutes.
