Heat oil in a deep fryer or large pot to 350°F (175°C).

Fry tortillas in hot oil until crispy and lightly browned, about 2-3 minutes per side.

Remove tortillas and drain on paper towels.

In a skillet, melt butter over medium heat.

Add hing and chili powder to the melted butter, stirring until fragrant.

Add cooked pinto beans and cumin powder to the skillet.

Mash the beans with a potato masher or fork until they form a thick paste.

If the bean paste is too thick, add a little water to make it spreadable.

Spread a layer of refried beans evenly over each fried tortilla.

Top the refried beans with shredded lettuce, sliced tomatoes, sliced black olives, and grated cheddar cheese.

Add a dollop of sour cream to each tostada.

For the Mexican Hot Sauce: Heat oil in a separate pan over medium heat.

Add hing and minced green chili pepper to the hot oil.

Fry until the chili pepper begins to brown, about 1 minute.

Add chili powder, lemon juice, and tomato puree to the pan.

Simmer uncovered for 5 minutes, or until the sauce slightly thickens.

Season the hot sauce with salt and turbinado sugar to taste.

Serve the Mexican Hot Sauce alongside the tostadas.