Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 450 degrees. Wash and dry produce.

Halve, core, and thinly slice green pepper crosswise into strips. Halve and peel onion; thinly slice one half. Finely chop remaining half until you have 2 TBSP. (For 4 servings, thinly slice both onion halves; finely chop a few slices until you have 3 TBSP.) Dice tomato. Zest and quarter lime.

Heat a drizzle of olive oil in a large pan over medium-high heat. Add pork* and Southwest Spice Blend; cook, breaking up meat into pieces, until browned, 3-4 minutes (it’ll finish cooking in the next step). TIP: If there’s excess grease in your pan, carefully pour it out.

Add green pepper and sliced onion to pan with pork. Cook, stirring occasionally, until veggies are tender and pork is cooked through, 5-7 minutes.

Add Tex-Mex paste and ¼ cup water (⅓ cup for 4 servings). Bring to a simmer and cook until thickened, 1-2 minutes. Season with pepper. Cover to keep warm.

While pork mixture cooks, drizzle tortillas with 1 TBSP olive oil (2 TBSP for 4 servings); brush or rub to coat both sides. Arrange on a baking sheet in a single layer. Gently prick each tortilla in a few places with a fork. (For 4, divide tortillas between two sheets; toast on top and middle racks, flipping tortillas and swapping rack positions halfway through toasting.)

Toast on top rack, flipping halfway through, until lightly golden, 4-5 minutes per side. TIP: Tortillas brown quickly—keep a close eye on them.

Meanwhile, in a small bowl, combine tomato, chopped onion, juice from half the lime, and a pinch of salt and pepper.

In a separate small bowl, combine sour cream, a squeeze of lime juice, and a pinch of lime zest to taste. Stir in water 1 tsp at a time until mixture reaches a drizzling consistency. Season with salt.

Remove baking sheet with toasted tortillas from oven; carefully sprinkle with Mexican cheese blend and Monterey Jack. Return to oven and bake until cheese melts, 1-2 minutes.

Divide cheesy tortillas between plates and top with pork mixture and pico de gallo. Drizzle with crema. Serve tostadas with any remaining lime wedges on the side.