Chili Crab Dip With Shrimp Chips

Name: Chili Crab Dip With Shrimp Chips
Ingredients: 2 medium shallots, quartered; 1 lemongrass stalk, bottom third only, tough outer layers removed, cut into a few pieces; 1 3–4 piece ginger, peeled, coarsely chopped; 1 serrano chile, preferably starting to turn orange, halved, seeds removed if desired; 4 medium garlic cloves; 2 Tbsp. double-concentrated tomato paste; 1 tsp. sugar; 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt, plus more; 1 Tbsp. vegetable oil; 4 oz. cream cheese, room temperature; 2 Tbsp. mayonnaise; 8 oz. claw crabmeat, picked over; 3 medium scallions, finely chopped; ½ large bunch cilantro, tough stems discarded, leaves and tender stems finely chopped; 2 Tbsp. store-bought fried shallots or garlic (optional); Shrimp chips (such as Dandy’s or Shrimp Snacks) or Ritz crackers (for serving)