Soak tapioca overnight in cold water (or 1–2 hours in hot water). Drain.
In a saucepan, heat milk, cream, and sugar until gently simmering. Stir in tapioca and cook on low 20–25 minutes, stirring often, until thickened and pearls are translucent.
Whisk eggs in a bowl. Slowly whisk in ½ cup hot pudding mixture, then pour back into the pot. Cook 2–5 more minutes until creamy and thickened. Stir in butter, salt, and vanilla.
Pour into a shallow dish and chill completely.
Top with sugar and broil 1–3 minutes until bubbling, then finish with a kitchen torch for a crackly brûléed top.
Toss berries with sugar and lemon juice. Let sit 20–30 minutes until juicy. Spoon over pudding and serve.
