Preheat a grill to medium low. Whisk the panko, brown sugar, 1/4 cup granulated sugar, the cinnamon, allspice, ginger and cloves in a medium bowl until combined. In another bowl, toss the rhubarb with the remaining 2/3 cup granulated sugar and the lemon juice to coat.
Butter a shallow 8-inch ovenproof skillet or flameproof baking dish. Sprinkle 3 tablespoons of the breadcrumb mixture in the bottom of the skillet. Top with the rhubarb, then sprinkle with the remaining crumbs and the almonds. Dot with the cut-up butter.
Put the skillet on the center of the grill; close the lid or place a disposable roasting pan over the skillet. Grill until the filling is bubbly and the topping is golden brown and crisp, 15 to 20 minutes. Let cool slightly, about 10 minutes. Serve warm and top with strawberry ice cream.